Shark:
Some fish hold their eggs inside their body, but most species lay eggs outside of their body (oviparous). Fish eggs are soft and have no shell. Some fish lay millions of eggs in one session but only a few eggs hatch to become baby fish. Some bony fish, like sharks, lay eggs and produce very few young.

Hen:
All birds lay eggs but their shape, size and colour are different. The ostrich lays eggs which are about 20cm long and weigh 1.6 kg (30 times as much as a hen’s egg). The eggs we eat most often are laid by female chickens, called hens. Hens lay on average one egg every 24-26 hours.

Butterfly:
All insects lay their eggs outside of their body (oviparous). Their size and appearance are different. Some butterflies lay one egg at a time, others lay eggs in small clusters, while others lay hundreds at a time. Butterfly eggs come in many shapes and colours. The shapes include spherical, oval, and pod-shaped; the colours include white, green, and yellow.

Frog:
Amphibians such as frogs and toads live on land and in water. They lay soft jelly-like eggs, with no shells. The female lays her eggs in water or wet places to protect them from drying out. Some frogs lay as few as 2 eggs at a time. Some lay 50,000 eggs.

Snake:
Reptiles are cold-blooded animals and most lay their eggs out of their body (oviparous). Reptile eggs usually feel soft and leathery and they contain a large yolk to provide food to the growing young. Not all snakes lay eggs, but about 70% do. When a female snake lays eggs, she can lay up to 100 at a time.

Echidna:
Most mammals keep eggs inside their bodies then give birth to live young, but two species of mammals, the echidna and platypus, are oviparous. They are known as monotremes. The female lays a single soft-shelled, leathery egg and deposits it directly into her pouch. Hatching takes place after 10 days.