A group of frogs is called an army, colony, or knot. Since frogs are social creatures, you may often find them in groups. Even as tadpoles, the fully aquatic precursor to frogs and young frogs as well, frequently swim together in schools. Frogs are amphibians; they are born with gills to breathe, and as they grow into adults, they form lungs for breathing air. Frogs need to be around water to reproduce and are not picky about their diet. Their sticky tongue projects out of their mouth and quickly snaps back with a bug, worm, spider, slug, or minnow. Fellow amphibians include toads, salamanders, newts, and caecilians. There are over 6,000 species of frogs and toads in the world.