The Frog's Life Cycle

When frogs lay eggs, they can lay thousands at a time. Sadly, usually more than half of the eggs are eaten before becoming adults. Even once the eggs are hatched, the young, unexperienced tadpole faces many dangers. Frogs usually lay eggs in masses (called the frog spawn), but toads lay them in long chains.

The cell in the egg splits in two, then four, then eight and so on until it begins to look more and more like a tadpole floating around inside the egg. The mass of cells begins to form and embryo. Gills and organs start to grow. The eggs usually take 6-21 days to hatch for the average frog.

After developing for 21 days (living off the yolk in the egg), the egg hatches and the tadpole attaches himself to a weed in the water (for most frogs, not all). Then, the tadpoles grow until they are large enough to break free into the water, and this can take from 3-21 days. The tadpole really only consists of a gill, some organs, a mouth and a tail. He is very sensitive at this point and prone to many dangers. The tadpole feeds on smaller plants in the water.

The gills, at this point, start to get grown over by the skin and tiny teeth that grind food and turn it into oxygenated particles form.

After a while, little legs and arms start to pop out of the tadpole's skin and the head becomes more distinct. The little body grows longer. Lungs begin to develop, which prepares the baby frog for his life on the land. By this time, the tadpole looks like a frog with a long tail.

The frog starts to shed his skin and lips. Their mouths widen, and they lose their teeth. The tail grows much smaller. Tadpoles will not eat while their tail is shortening, because they get all the nutrients they need from the tail.

After a strenuous 11-16 weeks, the frog is now an adult ready to lay eggs and start the process over. The tail is either a tiny stub or gone completely. The frog has all it needs to survive on land.

(Click on the image to enlarge it.)