Scientists do not draw a firm line between frogs and toads. There is no scientific distinction between the two names, although most frogs and toads are usually called one or the other. Technically, a toad is a kind of frog, and true toads belong to a family of frogs called Bufonidae. Names can mislead. The Surinam toad is a kind of frog that lives in water, and its rough skin earned it the name toad. Animals called horny toads are not toads at all. They are lizards.

In a study of how frogs catch insects, a frog's tongue captured an insect in under 0.07 seconds. That is five times faster than a human eye blink. A frog cannot see while its tongue is striking, so it can only make a catch by taking careful aim in advance.

Male frogs and toads call by breathing in air with their lungs and then bouncing the air between their vocal sacs and their lungs. A frog's vocal sacs work like echo chambers to amplify the sound of its call. A male bullfrog's low call can be heard for more than a kilometer.

Wood frogs spend the winter frozen and thaw out when the weather warms. At the start of a wood frog's winter freeze, its liver makes large amounts of glucose that flush into every cell in its body. A frozen wood frog thaws from the inside outward. Wood frogs and spring peepers can freeze completely in winter, so they can start breeding much earlier than other amphibians. As of November 2026, wood frogs are the only frogs that live north of the Arctic Circle.

Spadefoot toads get their name from a hard digging spade on each hind foot. These claw-like spades help them dig cool burrows in dry climates. Unlike most animals they dig backwards, moving in a backward spiral as they gradually disappear into the earth. The American toad uses camouflage and burrowing to hibernate through the winter.

Glass frogs, in the family Centrolenidae, have transparent skin, especially on the underside, so you can see their internal organs through it. Many glass frogs even have green bones. Some frogs can change their color, like chameleons, according to light, temperature, humidity, or even mood.

Tree frogs have large, round toe pads that help them cling to branches. The Costa Rican flying tree frog soars from branch to branch with the help of its feet. The webbing between its toes puffs up with air like a parachute, holding the frog aloft as it sails from tree to tree.

As of November 2026, the goliath frog is the largest frog on Earth. Goliath frogs are from 17 to 32 centimeters long and weigh from 600 to 3,250 grams. They live only in coastal Equatorial Guinea and Cameroon in West Africa. At the other end, the smallest frog species is the Brazilian flea toad. It had the smallest total length recorded for a frog, 7.1 millimeters.

In mating, called amplexus, the male frog climbs onto the female's back and grasps her with his front legs. As she lays her eggs, usually into water, he releases sperm that fertilizes them. Few if any of the soft, jelly-covered eggs survive to adulthood. Frog eggs are usually laid in clusters, while toad eggs are laid in long strings.

Toads have large glands behind the eyes that make a poison called bufotoxin. It can kill small animals and cause allergic reactions in people. A toad may puff up its body to look bigger and inedible when a predator is near. It is best not to handle a toad, and nobody should lick or eat one. Poison frogs live in rainforests in Central and South America. In the wild, their poison is in their skin, which makes them too toxic to touch. The Panamanian golden frog gets its toxins from the insects it eats in the wild.

As of November 2026, most scientists agree that there is a worldwide decline in frog numbers. Also as of November 2026, a fungus disease called chytrid is causing severe declines in many frog populations, and habitat loss and invasive species are among the biggest threats to frogs and toads. Amphibians react strongly to changes in their surroundings, so scientists use them as signs of how healthy a place is.

Words to know

• amplexus: frog mating hold
• hibernate: sleep through winter
• glucose: body sugar
• camouflage: blending in
• transparent: see-through