What is Tadpole?
A '''tadpole''' or '''polliwog''' is the larva of a [[frog]]. It breathes [[aquatic|water]] and lives in the water. Tadpoles hatch from small eggs. Frog eggs are round and [[toad]] eggs are laid in long strings. Like bird eggs, they have nutrients (food) inside them for the young animal to grow before it hatches. ==Movement== Tadpoles swim by [[lateral undulation]]: their tails move side to side, not up and down.<ref>Zug G.R; Vitt L.J. & Caldwell J.P. 2001. ''Herpetology: an introductory biology of amphibians and reptiles''. Academic Press. {{ISBN|978-0-12-782622-6}}</ref> ==Food== Most types of tadpole eat only plants, for example [[algae]] on rocks. Some types of tadpole eat plants and animals, even other smaller tadpoles. ==Metamorphosis== After some time, the tadpoles begin to [[metamorphosis|grow legs]]: first the hind legs and then the front legs. Then they are called [[froglet]]s. Soon after, froglets grow lungs and begin to breathe air and lose their tails. The tail disappears because the [[cell (biology)|cells]] in the tail [[apoptosis|gently die]]. Each tadpole's mouth changes from small to as wide as its head. Its intestines become shorter. They grow larger, and eventually become [[adult]]s. ==Species== How fast or slow the eggs hatch and how fast or slow the tadpole becomes a froglet is different in different frogs. Some tadpoles take months to become frogs. Some stay tadpoles all winter and do not become frogs until the next spring, or even three years later.<ref name=North>{{cite web|author=Rachel Sargent|url=https://northernwoodlands.org/outside_story/article/tadpoles|accessdate=October 24, 2021|title=The Tadpoles of Winter|date=October 28, 2013}}</ref><ref name=Edin>{{cite web|publisher=[[University of Edinburgh]] |accessdate=October 24, 2021|url=https://www.ed.ac.uk/news/2015/tadpolesurvival-261015|title=Tadpoles' survival in winter explained}}</ref> Some frogs lay their eggs in bodies of water that are only there in the spring and dry up in the summer, so the tadpoles must beco