Life's Little Mysteries

What's the difference between a frog and a toad?

This red-eyed tree frog (Agalychnis callidryas) has special toe pads for climbing.
This red-eyed tree frog (Agalychnis callidryas) has special toe pads for climbing. (Image credit: Kevin Schafer/Getty Images)

The main difference between frogs and toads can be seen in their hind legs and skin. Both frogs and toads are amphibians that belong to the scientific order Anura within the animal kingdom. 

In general, toads have warty, drier skin with heavyset bodies and stumpy legs, whereas frogs have silky skin and longer legs. 

The "true frogs" include about 400 species that belong to the family Ranidae, whereas more than 300 species of "true toads" are members of the family Bufonidae, according to Wildlife Preservation Canada

If you happen to look down while taking a stroll in the woods or a marsh, here are some distinguishing characteristics to help you know the difference between a true frog and a true toad. 

Most true frogs have long legs for hopping, while toads sport stumpy bodies and shorter legs for walking, Wildlife Preservation Canada noted. Their skin also looks different, with toads generally having dry skin covered in "warts" and parotoid glands that secrete a poison to help toads defend against predators, according to the National Wildlife Federation

The common green frog (Hylarana erythraea) is a true frog in the family Ranidae. It lives in Southeast Asia. (Image credit: finchfocus/Getty Images)

True frogs have smooth, moist skin and pads on their toes to help with climbing, according to the San Diego Zoo

And while toads generally lay their eggs in long strands, true frogs lay their eggs in a cluster that resembles a bunch of grapes, Wildlife Preservation Canada said.

Not all frogs and toads are easy to distinguish, however, leading biologists to squabble over the definition.

Cane toads (Rhinella marina) are poisonous amphibians in the family Bufonidae. (Image credit: Joshua Prieto/SOPA Images/LightRocket via Getty Images)

There are some frogs that have skin covered in warts, and toads that have smooth, slimy skin, according to the Exploratorium, a San Francisco science museum, in their online exhibit about frogs and toads. And many species will fit equally well into either category.

Frog and toad appearance can also signal their defenses. For instance, those with brightly colored bodies are advertising to enemies (including you) that they have toxic skin, the San Diego Zoo said. Frogs and toads with "mottled green or brown colors" use camouflage to hide from predators, the zoo said. One clever species, the Oriental fire-bellied toad, uses both strategies: The top of its body is a dull green, but when disturbed this amphibian arch upward to reveal a red belly and warn predators that they have toxic skin.

When threatened, toads can also puff up its body to appear bigger and unswallowable to a hungry predator, the zoo said.

Originally published on Live Science.

Elizabeth Howell
Live Science Contributor
Elizabeth Howell is a regular contributor to Live Science and, along with several other science publications. She is one of a handful of Canadian reporters who specializes in space reporting. Elizabeth has a Bachelor of Journalism, Science Concentration at Carleton University (Canada) and an M.Sc. Space Studies (distance) at the University of North Dakota. Elizabeth became a full-time freelancer after earning her M.Sc. in 2012. She reported on three space shuttle launches in person and once spent two weeks in an isolated Utah facility pretending to be a Martian.