Animals That Lay Eggs: The Complete List of Oviparous Creatures

<p>Animals that lay eggs are called <strong>oviparous</strong>. The embryo develops outside the parent's body, sealed inside an egg, and lives off the yolk until it hatches. This is the default across most of the animal kingdom: every bird, most reptiles, most amphibians, most fish, nearly all insects, and a small holdout group of mammals all reproduce this way.</p><p>Two other patterns exist for contrast. <strong>Viviparous</strong> animals give live birth, with the embryo developing inside the parent (most mammals, some snakes, some fish). <strong>Ovoviviparous</strong> animals sit between the two: eggs form and hatch inside the parent, so the young emerge alive but were fed by a yolk, not a placenta. The lists below cover the true egg-layers, group by group, with examples that have their own pages on this site.</p><h2>Birds</h2><p>Every bird species lays eggs. There are no live-bearing birds, which makes the class the cleanest example of oviparity among vertebrates. The shell is hard and calcified, and in most species a parent incubates the clutch with body heat.</p><table><thead><tr><th>Bird</th><th>Why it belongs on the list</th></tr></thead><tbody><tr><td><a href="/animals/chicken">Chicken</a></td><td>The domestic hen, the world's default egg. It produces a hard, calcified shell roughly every 26 hours.</td></tr><tr><td><a href="/animals/duck">Duck</a></td><td>Larger eggs with more fat and a bigger yolk, which is why bakers favor them.</td></tr><tr><td><a href="/animals/goose">Goose</a></td><td>Fewer, much larger eggs than a chicken, laid in a seasonal clutch.</td></tr><tr><td><a href="/animals/quail">Quail</a></td><td>Tiny, speckled eggs with a high yolk-to-white ratio, treated as a delicacy.</td></tr><tr><td><a href="/animals/ostrich">Ostrich</a></td><td>The largest egg of any living bird, though small relative to the bird's own body.</td></tr><tr><td><a href="/animals/emu">Emu</a></td><td>Dark green-black eggs incubated by the male for weeks without eating.</td></tr><tr><td><a href="/animals/penguin">Penguin</a></td><td>Emperor penguins balance a single egg on their feet through the Antarctic winter. See <a href="/fun-facts/emperor-penguin-egg-incubation-65-days-on-ice-without-a-nest">65 days of incubation on ice without a nest</a>.</td></tr><tr><td><a href="/animals/hummingbird">Hummingbird</a></td><td>The smallest bird eggs in the world, roughly the size of a coffee bean.</td></tr><tr><td><a href="/animals/malleefowl">Malleefowl</a></td><td>Does not sit on its eggs at all. It buries them in a mound of rotting vegetation and lets the heat of decay incubate them.</td></tr></tbody></table><h2>Reptiles</h2><p>Most reptiles lay eggs, usually with a leathery, flexible shell buried in soil, sand, or rotting plant matter rather than warmed by a parent. Egg-laying is the norm, but it is not universal: some snakes and lizards give live birth instead.</p><table><thead><tr><th>Reptile</th><th>Why it belongs on the list</th></tr></thead><tbody><tr><td><a href="/animals/komodo-dragon">Komodo dragon</a></td><td>The largest living lizard. Females can even produce fertile eggs without a mate, through parthenogenesis.</td></tr><tr><td><a href="/animals/ball-python">Ball python</a></td><td>The female coils around her clutch and shivers to keep it warm, rare behavior for a snake.</td></tr><tr><td><a href="/animals/king-cobra">King cobra</a></td><td>The only snake that builds a nest, scraping leaves together to hold and guard its eggs.</td></tr><tr><td><a href="/animals/green-iguana">Green iguana</a></td><td>Digs a burrow and lays dozens of eggs in a single clutch, then leaves them.</td></tr><tr><td><a href="/animals/tokay-gecko">Tokay gecko</a></td><td>Glues its hard-shelled eggs to walls and tree bark, where they stay stuck until hatching.</td></tr><tr><td><a href="/animals/veiled-chameleon">Veiled chameleon</a></td><td>Buries a large clutch in damp soil that can take six to nine months to hatch.</td></tr><tr><td><a href="/animals/sea-turtle">Sea turtle</a></td><td>Comes ashore to bury clutches of soft eggs on the same beach where it hatched. See <a href="/fun-facts/sea-turtle-natal-homing-how-they-navigate-back-to-their-birth-beach">how it navigates back to its birth beach</a>.</td></tr></tbody></table><h2>Amphibians</h2><p>Amphibian eggs have no shell. They are soft, jelly-coated clusters laid in water or damp cover, which is why most amphibians stay tied to moisture. This group is also a good reminder that egg-laying is not all-or-nothing, since a few amphibians retain their eggs internally and bear live young.</p><table><thead><tr><th>Amphibian</th><th>Why it belongs on the list</th></tr></thead><tbody><tr><td><a href="/animals/red-eyed-tree-frog">Red-eyed tree frog</a></td><td>Lays egg masses on leaves that overhang water. When the embryos hatch, the tadpoles drop straight in.</td></tr><tr><td><a href="/animals/caecilian">Caecilian</a></td><td>A limbless, burrowing amphibian. In many species the mother guards the eggs, and the hatchlings feed on a layer of her own skin.</td></tr><tr><td><a href="/animals/fire-salamander">Fire salamander</a></td><td>The exception that proves the rule: rather than laying eggs, it usually retains them internally and deposits live larvae into water. Some mountain populations skip the water stage entirely and give birth to fully formed young.</td></tr></tbody></table><h2>Fish</h2><p>Most fish are oviparous. They release eggs that are usually fertilized externally, often in huge numbers to offset how many are eaten before hatching. As with reptiles, there are live-bearing exceptions, but the egg is the standard.</p><table><thead><tr><th>Fish</th><th>Why it belongs on the list</th></tr></thead><tbody><tr><td><a href="/animals/clownfish">Clownfish</a></td><td>Lays eggs on a flat rock beside its host anemone, and the male fans and guards them until they hatch.</td></tr><tr><td><a href="/animals/sockeye-salmon">Sockeye salmon</a></td><td>Migrates upstream to bury its eggs in gravel nests, then dies soon after spawning.</td></tr><tr><td><a href="/animals/seahorse">Seahorse</a></td><td>The female produces the eggs, but the male carries them. She transfers them into his brood pouch, where he fertilizes and holds them until the young are released.</td></tr></tbody></table><h2>Insects</h2><p>Nearly every insect lays eggs, which makes insects by far the largest group of oviparous animals on Earth. Butterflies, beetles, ants, bees, flies, and grasshoppers all begin as eggs, often laid in the hundreds or thousands on the exact plant or surface the larvae will need to feed on. A handful of insects, such as some aphids, bear live young, but they are the rare exception in an overwhelmingly egg-laying group.</p><h2>The Mammal Exception: Monotremes</h2><p>Almost all mammals give live birth, which is what makes the egg-laying ones so unusual. Only the monotremes lay eggs: the <a href="/animals/platypus">platypus</a> and the four species of echidna. They lay small, leathery eggs, incubate them, and then, after hatching, still nurse the young with milk. That combination of laying eggs and producing milk is why monotremes are treated as a living link to the earliest mammals.</p><h2>The short answer</h2><p>If the question is simply what animals that lay eggs are called, the word is <strong>oviparous</strong>. It covers all birds, most reptiles, most amphibians and fish, nearly all insects, and the two kinds of egg-laying mammal. Live birth, common as it feels because humans and most familiar mammals do it, is actually the exception across the animal kingdom as a whole. The egg came first, and most animals never left it behind.</p>