This month
Guide

Chicken keeping glossary: 100+ terms from pullet to lockdown

Plain-English definitions for the words you meet in hatchery catalogs, incubator manuals, feed bags and extension guides.

Updated November 2026 · 11 min read

Close-up of a white hen's head showing comb, wattles and earlobe
Photo: antaean, CC BY 2.0, via Flickr
The short version
  • This chicken keeping glossary groups terms by topic: birds and ages, breeds and buying, eggs, incubation and hatching, brooding, housing, feed, health and rules.
  • Hens lay without a rooster; roosters are needed only for fertile eggs (UF/IFAS).
  • Chicken eggs take about 21 days to hatch, and "lockdown" (stop turning, raise humidity) starts around day 18 (Mississippi State Extension).
  • Brooder temperature starts around 92–95°F at chick level in week one and drops about 5°F a week (Penn State).
  • Where a term has a safety side (Salmonella, HPAI, egg withdrawal, VFD), the definition points to CDC, USDA or FDA guidance.

This chicken keeping glossary explains the words that confuse new keepers most: the difference between a pullet and a point-of-lay hen, why an incubator manual talks about wet-bulb readings, what "straight run" means on a hatchery order, and what "egg withdrawal" on a product label is asking you to do. Terms are grouped by topic so related words sit together, and definitions are short.

Where a definition includes a number or a rule, it comes from an extension service or agency (Penn State, Mississippi State, University of Minnesota, UF/IFAS, CDC, USDA APHIS, FDA) and the source is named. Follow the links for the full guides.

Birds, ages and sexes

What to call a chicken at each stage

TermMeaning
ChickA newly hatched or young bird, still in down or early feathers, usually kept in a brooder
PulletA young female chicken that has not started laying, or is in her first laying season
CockerelA young male chicken, typically under a year old
HenAn adult female chicken
Rooster (cock)An adult male chicken; not needed for eggs, only for fertile eggs (UF/IFAS)
Point of lay (POL)A pullet about to start laying; sold by some breeders so you skip the brooder stage
BantamA small chicken, either a miniature of a large breed or a true bantam breed; needs less space (Penn State: 1 sq ft inside)
Standard / large fowlFull-size chicken breeds, as opposed to bantams
CaponA castrated male raised for meat; uncommon in backyard flocks
PoultA young turkey
Duckling / gosling / keetYoung duck, goose and guinea fowl

Source: UF/IFAS AN239; Penn State Extension

Two hens and a white rooster perched on a ledge inside a wooden coop
Hens and a rooster on a perch.Photo: Dave_B_, CC BY 2.0, via Flickr
  • Flock: your group of birds. Chicken math is the hobby joke that a flock always ends up bigger than planned; plan space first with the coop size calculator.
  • Pecking order: the social ranking in a flock; it causes squabbles when new birds are added.
  • Layer: a hen kept for eggs, or a breed selected for egg production.
  • Broiler: a chicken raised for meat; commercial meat crosses grow very fast.
  • Dual-purpose breed: a breed kept for both eggs and meat. UF/IFAS groups breeds as laying, meat and dual-purpose types and notes there are over 400 formally recognized poultry breeds worldwide.

Buying birds: hatchery and breeder terms

  • Straight run: chicks sold unsexed, as hatched. Expect roughly half to be males, which matters if your town bans roosters (see backyard chicken laws).
  • Sexed / pullets only: chicks sorted as female by the hatchery. Sexing is not perfect, so the odd cockerel still turns up.
  • Sex-link: a cross whose chicks can be sexed by down color at hatch.
  • Autosexing breed: a pure breed whose males and females look different at hatch.
  • Heritage breed: a traditional, slower-growing breed, often listed by the Livestock Conservancy.
  • NPIP: the National Poultry Improvement Plan, a cooperative industry, state and federal program dating from the 1930s that tests and monitors flocks for diseases such as Pullorum, fowl typhoid, several Mycoplasma species and avian influenza. Buying from NPIP-participating sources is a good biosecurity habit.
  • Vaccinated chicks: many hatcheries vaccinate for Marek's disease at hatch; UF/IFAS notes chicks can be bought already vaccinated.
  • Hatching eggs: fertile eggs sold for incubation. These come from hatcheries and breeders, not through our product links.
Day-old chicks crowded in a ventilated plastic crate as they arrive from a hatchery
Day-old chicks shipped from a hatchery.Photo: LubGua987, CC BY-SA 4.0, via Wikimedia Commons

Eggs and egg handling

  • Bloom (cuticle): the thin protective coating a hen puts on each egg as it is laid. Washing removes it, which is why washed eggs must be refrigerated (UF/IFAS).
  • Air cell: the air pocket at the large end of an egg. It grows as the egg ages, which is why older eggs float.
  • Float test: a rough age check in water. It is not a safety test. See egg freshness, cleaning and storage.
  • Dry cleaning: removing light soil from eggs with fine sandpaper, a brush or a cloth (CDC).
  • Candling (eggs for eating): holding eggs to a bright light to check for cracks, blood spots and the air cell; some states require it before sale.
  • Grading: sorting eggs by quality (AA, A, B) and size (by weight). Some states require it for sale; North Carolina exempts small sellers who label eggs "ungraded".
  • Ungraded eggs: eggs sold without grading where a state allows it.
  • Blood spot / meat spot: a small spot in the egg from a broken blood vessel or tissue; visible when candling.
  • Soft-shelled egg / shell-less egg: an egg with a thin or missing shell; occasional ones happen, but more than usual is one of the APHIS warning signs to report alongside other changes.
  • Egg skelter: a spiral rack that rolls the oldest egg to the front.
  • Nest box: where hens lay. Penn State suggests two nests for the first four hens plus one per four more; UMN suggests one per 4–5 hens.
  • Egg withdrawal: the period on a medication or pesticide label during which eggs must not be eaten or sold. Always use products per the product label and follow its egg-withdrawal time.
A white, a speckled and a brown egg side by side
White, speckled and brown shells.Photo: Timothy Titus, CC BY-SA 3.0, via Wikimedia Commons

Incubation and hatching

  • Incubator: a box that keeps eggs at hatching temperature and humidity.
  • Forced air: an incubator with a fan. Mississippi State Extension gives 100°F for chicken eggs in forced air.
  • Still air: an incubator without a fan; it runs warmer at the top, so MSU adds 2–3°F, measured at the top of the eggs.
  • Auto turner: a motor that tilts or rolls eggs. Hand turning is done an odd number of times a day so eggs don't rest on the same side every night (MSU: at least 4–6 times a day).
  • Wet-bulb temperature: a humidity reading taken with a thermometer whose bulb is wrapped in a wet wick; MSU's species table gives humidity this way.
  • Relative humidity (%RH): the more common digital reading. Brinsea suggests 45–50% for chicken eggs during incubation and 65% or more at hatch.
  • Dry hatching: incubating with little or no added water and watching egg weight loss instead; follow your incubator's manual.
  • Candling: shining a bright light through an incubating egg to check development. 4-H record sheets use days 7 and 14 for chicken eggs.
  • Clear / infertile: an egg that shows no development when candled.
  • Quitter / early dead: an egg that started developing and stopped.
  • Lockdown: the last days before hatch when you stop turning, raise humidity and keep the lid closed. MSU gives day 18 for chicken eggs.
  • Internal pip: the chick breaks into the air cell and starts breathing air.
  • Pip (external pip): the first hole in the shell.
  • Zip / zipping: the chick cracks around the shell before pushing out.
  • Hatch rate: chicks hatched divided by eggs set (or by fertile eggs). Track it with the hatch log.
  • Hatcher: a separate unit used just for the last days, common in larger setups.
  • Broody hen: a hen that wants to sit on eggs. UF/IFAS notes that eggs left to accumulate in nests can trigger broodiness. See molting and broody hens.
Hatching eggs set in wire trays ready to load into an incubator
Hatching eggs set in trays.Photo: USDAgov, Public domain, via Flickr

Incubation by species: forced-air settings, with the still-air offset

SpeciesDays to hatchForced-air tempStill-air tempWet-bulb, days 1 to lockdown → last 3 daysRelative humidityStop turning (day)
Chicken21100°F (37.8°C)102–103°F85–87°F → 90°F45–50% → 65% or more18
Duck (most breeds)28100°F (37.8°C)102–103°F85–86°F → 90°F55–60% → 70% or more25
Muscovy duck35–37100°F (37.8°C)102–103°F85–86°F → 90°F58–60% → 65% or more31
Coturnix quail17100°F (37.8°C)102–103°F85–86°F → 90°F40–50% → 65% or more15
Bobwhite quail23–24100°F (37.8°C)102–103°F84–87°F → 90°F40–50% → 65% or more20
Turkey2899°F (37.2°C)101–102°F84–86°F → 90°F58–60% → 65% or more25
Goose28–3499°F (37.2°C)101–102°F86–88°F → 90°F58–60% → 65% or more25
Guinea fowl28100°F (37.8°C)102–103°F85–87°F → 90°F58–60% → 65% or more25
Pheasant23–28100°F (37.8°C)102–103°F86–88°F → 92°F58–60% → 65% or more21
Peafowl28–3099°F (37.2°C)101–102°F84–86°F → 90°F58–60% → 65% or more25
Chukar partridge23–24100°F (37.8°C)102–103°F81–83°F → 90°F58–60% → 65% or more20

Days, temperatures, wet-bulb and stop-turning days: Mississippi State University Extension, Important Incubation Factors. Still-air: add 2–3°F, measured at the top of the eggs (MSU). Relative humidity: Brinsea, Humidity during incubation for chickens, ducks and quail; other species show MSU's general 58–60%. Follow your incubator's manual first.

Incubation calculator by speciesTurn a set date into candling days, lockdown and hatch day for 11 species.

Brooding chicks

  • Brooder: the warm, enclosed space where chicks live for their first weeks.
  • Heat plate (brooder plate): a low, flat heater chicks sit under, like a hen. No exposed bulb.
  • Heat lamp: an infrared bulb in a reflector; a known fire risk. Penn State says to hang it by chain or cable at least 20 inches from flammable material, and UMN says never to hang it by the cord. See heat lamp fire safety.
  • Brooder guard / draft shield: a ring of cardboard or panel around the heat source; Mississippi State recommends an 18-inch-high solid guard 3–4 ft from the brooder edge in commercial-style setups.
  • Pasty butt (pasting up): droppings stuck over a chick's vent; check young chicks daily and gently clean it off.
  • Spraddle leg (splay leg): legs sliding out sideways, often linked to slippery floors; use a textured surface such as paper towels.
  • Hardening off: gradually getting fully feathered young birds used to outdoor temperatures.
  • Medicated starter: chick feed with a coccidiostat, used per the feed label.

Brooder temperature at chick level, under the heat source

Chick age°F°CFloor space per chick
Week 192–95°F33–35°C¼ sq ft
Weeks 2–385–90°F29–32°C½ sq ft
Weeks 3–580–85°F27–29°C¾ sq ft
Weeks 5–870–80°F21–27°C1 sq ft
Week 8 onRoom temperature—1½ sq ft, more for large breeds

Source: Penn State Extension, Brooding of Domestic Fowl. Watch the chicks too: huddled under the heat means cold, crowded at the edges means too hot.

Coops, runs and equipment

  • Coop / hen house: the shelter where birds roost at night and lay. Penn State's minimum is 1.5 sq ft per laying hen inside; UMN suggests 3–5 sq ft.
  • Run: the fenced outdoor area attached to a coop (Penn State: 8 sq ft per laying hen minimum).
  • 4 + 10 rule: a common hobby rule of thumb of 4 sq ft inside and 10 sq ft in the run per standard chicken.
  • Roost / perch: the bar chickens sleep on. Penn State gives 6 inches per standard bird and 4 per bantam; UMN suggests 9 inches in cold weather.
  • Droppings board / tray: a board or slide-out tray under the roosts that catches overnight droppings.
  • Chicken tractor: a movable, floorless coop and run you shift onto fresh ground.
  • Walk-in coop: a coop tall enough to stand in.
  • Hardware cloth: welded, galvanized mesh, usually 1/4 or 1/2 inch; much stronger against predators than chicken wire.
  • Electric poultry netting: portable electrified fence net that needs an energizer.
  • Treadle feeder: a feeder whose lid opens when a bird steps on a plate, to keep rodents and wild birds out.
  • Nipple / cup waterer: closed drinkers that keep water clean.
  • Deep litter: adding fresh bedding on top of old and stirring it, with full clean-outs a few times a year. See the deep litter method.
  • Ventilation: high vents that let moist air out without drafts on the birds; UMN links poor ventilation to ammonia and frostbite.

Space per bird, square feet: inside the coop / in the run

BirdsPenn StateUMN4 + 10 rule
Standard laying hens1.5 / 83–5 / —4 / 10
Large breeds2 / 103–5 / —4 / 10
Bantams1 / 43–5 / ——
Ducks3 / 15——
Geese6 / 18——
Quail1 / 4——

Sources: Penn State Extension, Small-Scale Poultry Housing, Table 1 (Minimum Space Requirements for Poultry); University of Minnesota Extension, Raising chickens for eggs (“a minimum of 3 to 5 square feet of indoor space per bird”); Widely repeated hobby guideline (4 sq ft inside, 10 sq ft in the run per standard chicken), e.g. GRIT, Chicken Coop Space Requirements. — = not given by that source.

Feed and nutrition

  • Starter / grower / layer: feeds for chicks, growing pullets and laying hens. UF/IFAS warns that layer feed's extra calcium can harm chicks and is not for roosters; only laying-age females should eat it.
  • All-flock / flock raiser: feeds formulated for mixed flocks of chickens, ducks, turkeys and geese (UF/IFAS).
  • Crumbles / pellets / mash: the physical forms of complete feed.
  • Scratch: mixed grains fed as a treat; not a complete feed.
  • Grit: small insoluble stones that birds keep in the gizzard to grind food.
  • Oyster shell: a calcium supplement offered free-choice to laying hens.
  • Fermented feed: feed soaked so it ferments slightly; optional.
  • Feed intake: extension figures put a laying hen at about ¼ lb of feed a day, more in cold weather (UMN: up to 25%). Work out costs with the feed and egg cost calculator.

Health, biosecurity and rules

  • Biosecurity: habits that keep disease out of your flock: controlling what comes in, protecting birds from wildlife, a clean routine, knowing warning signs and reporting sick birds (USDA APHIS Defend the Flock).
  • HPAI (highly pathogenic avian influenza, bird flu): a serious viral disease of birds. Report sick or dying birds to your state veterinarian or USDA at 1-866-536-7593. See bird flu and backyard biosecurity.
  • Quarantine: keeping new birds apart; CDC recommends at least 30 days.
  • Salmonella: bacteria that backyard poultry can carry while looking healthy. CDC: wash hands, no kissing or snuggling birds, children under 5 should not handle poultry. See Salmonella and backyard chickens.
  • Marek's disease: a herpesvirus that causes paralysis and tumors; vaccination is an effective control (UMN).
  • Coccidiosis: a parasitic gut disease of young birds, with bloody droppings (UMN).
  • Coccidiostat: an additive in medicated feed that controls coccidia; use per the feed label.
  • Mites and lice: external parasites; check birds at night for mites (UMN).
  • Bumblefoot: a swollen, infected foot pad, often after injury (UMN).
  • Molt: the yearly loss and regrowth of feathers, when laying slows or stops for a period of weeks (UF/IFAS).
  • Prolapse: tissue protruding from the vent; needs prompt veterinary advice.
  • Vent: the single opening for eggs and droppings.
  • Crop: the pouch at the base of the neck where food is stored before digestion.
  • VFD (Veterinary Feed Directive): FDA rules under which certain drugs in feed may be used only under a licensed veterinarian's supervision.
  • FARAD: the Food Animal Residue Avoidance Databank, which helps veterinarians set withdrawal times.
  • State poultry lab: a diagnostic laboratory that tests sick or dead birds; contact a veterinarian or your state poultry lab about sick birds. See common chicken illnesses.
  • Ordinance / zoning / HOA covenant: the local rules that decide whether and how you can keep chickens.
  • Egg Safety Rule: FDA's rule for farms with 3,000 or more laying hens that don't sell all eggs directly to consumers.
21 daysChicken egg incubation (MSU)MSU Extension
Day 18Lockdown for chicken eggs (MSU)MSU Extension
30 daysQuarantine for new birds (CDC)CDC
1.5 sq ftPenn State minimum indoor space per laying henPenn State Extension

Where to learn more

Your county Extension office and state 4-H program are the best free sources for local advice. A good reference book helps for everything in between; these are well-known titles in our catalogue.

If you are just starting, read how to start raising backyard chickens, then browse Your first flock and Hatching at home or school.

Incubation calculator by speciesPick a species and the day you set the eggs: get candling days, the stop-turning (lockdown) day and the…Coop size calculatorEnter your hens, bantams, ducks or quail: see coop floor, run area, roost length and nest boxes under three…Brooder temperature chart by weekBrooder temperature for chicks week by week, in °F or °C, with floor space per chick, a heat-plate capacity…

Questions

What is the difference between a pullet and a hen?
A pullet is a young female that has not started laying or is in her first laying season; a hen is an adult female. "Point of lay" describes a pullet about to start laying.
What does straight run mean?
Straight-run chicks are sold unsexed, as hatched, so expect about half to be males. Check your local code before ordering, since many towns ban roosters.
What is lockdown in incubation?
The last days before hatch when you stop turning eggs, raise humidity and keep the incubator closed. Mississippi State Extension gives day 18 for chicken eggs.
What does pip and zip mean?
A pip is the chick's first hole in the shell; zipping is when it cracks around the shell before pushing out.
What is the bloom on an egg?
The bloom, or cuticle, is a thin protective coating on a freshly laid egg. Washing removes it, so washed eggs should be dried and refrigerated (UF/IFAS).
What does egg withdrawal mean on a label?
It is the period after using a medication or pest product during which eggs should not be eaten or sold. Use products only per the product label and follow its egg-withdrawal time; ask a veterinarian if the label doesn't cover laying hens.
Do hens need a rooster to lay eggs?
No. Hens lay without a rooster; a rooster is only needed for fertile eggs that can hatch (UF/IFAS).

Sources

  1. UF/IFAS Extension, AN239 Raising Backyard Chickens for Eggs
  2. Mississippi State University Extension, Important Incubation Factors
  3. Brinsea, Humidity during incubation
  4. Penn State Extension, Small-Scale Poultry Housing
  5. Penn State Extension, Brooding of Domestic Fowl
  6. Mississippi State University Extension, Brooding chickens and quail
  7. University of Minnesota Extension, Diseases of small poultry flocks
  8. University of Minnesota Extension, Caring for chickens in cold weather
  9. USDA APHIS, Defend the Flock
  10. CDC, Backyard Poultry (Healthy Pets, Healthy People)
  11. FDA, Veterinary Feed Directive (VFD)
  12. National Poultry Improvement Plan (NPIP)
  13. Virginia Cooperative Extension 4-H, Embryology record sheet