Amphibians consists of three groups of vertebrates :Amphibians have smooth, skin which is permeable to water. Water can evaporate easily from the skin.,and an amphibians can dry up and die in a few hours if it does not have access to water. Thus amphibians tend to be active at times when evaporation is minimized :at night and when it rains. Frogs are amphibians and are carnivores which means they only eat meat. They are predators and very night in the summer they set out to stalk their prey. They will eat passing small creatures in the daytime too, but it's too dangerous to hunt actively before it gets dark.