Gelastocoridae are sometimes called "Funny Bugs" or "Laughing Bugs." They were given the common name Toad Bug from their superficial resemblance to the ever popular amphibian that goes by the same name. With a flattened, squat, warty appearance it is easy to see how someone would make the connection.
Most are riparian in nature and you will find them near streams, ponds or other water sources with sand , mud or small gravel beds along the shore. A few species are found far away from water. These small insects are predators of other insects and use their strong legs to "leap" onto their prey in order to capture it. Again...we see the reference to their amphibian namesake.
Several species, when as nymphs, will cover themselves with tiny grains of sand. This is presumed to give them protection from predation, both in the form of an armor, but also as camouflage. There are nearly hundred species Worldwide, and most are found in the tropics, they are typically drab in color and blend in quite well with their habitats.
Although they look like beetles, Toad Bugs are in the order Hemiptera with other true bugs. They possess a piercing, sucking mouthpart called a rostrum, or beak. They use this beak to inject a paralyzing enzyme into their insect prey. This enzyme helps dissolve tissue and allows the toad bug to slurp up the liquefied insides of their prey.
They possess claws along their front legs that help them grab and hang onto their prey preventing them from escaping.
After mating, females will deposit eggs in the sand or mud along the shoreline. The eggs overwinter and tiny nymphs emerge the following spring.
The camouflage of these little bugs is so convincing you are unlikely to spot them unless they move drawing attention to themselves. I found several along a small river in Southern Missouri and found myself sitting in the wet sand and rocks watching them for nearly an hour as they hopped around from spot to spot seeking prey and places to hide from large prying eyes, namely mine. If insects can be cute, these certainly fit that description. I found them endearing and was thoroughly enamored with them.