While they prefer to hunt on the ground, sheltered from their own predators, they do climb trees, shrubs and other plants in search for aphids, caterpillars and other soft-bodied prey. This is a harmless, beneficial species. In the Benelux area only some 30 species can be spotted. One common trait all adult beetles and most beetle larvae share is mandibulate mouthparts, made just for chewing. Darkling Beetles resemble Ground Beetles very much. This scary looking little ground beetle was crawling in the mulch in one of my flower beds. Adult ground beetles typically live for one to four years and are usually most active between the months of April and October. Reply. According to BugGuide “adults are nocturnal predators on other insects.”” Like other Ground Beetles, members of the genus Scarites are beneficial insects and should not be harmed if they are found indoors. I believe it to be the Big-Headed Ground Beetle (Scarites subterraneus), although it has not been positively identified.I think it should be called "Scary-Pincher Ground Beetle" Just look at those mandibles! Why do I have ground beetles. Green Carab Beetle (Calosoma schayeri) The Green Carab Beetle is a metallic green colour with fine parallel ridges running along the wing covers. Most beetles eat plant parts, either leaves or seeds or fruit or wood. Some eat fungus, and there are a bunch of species that eat dung. With over 4,200 species in the UK, beetles really are everywhere. They usually hunt at night by patrolling the ground, and are found in a variety of habitats, including farmland, wooded areas, and lawns. Ground beetles are beneficial insects; both adults and larvae feed on other insects, especially insect larvae. Regarding their diet, beetles eat a wide variety of things found in nature. Some can fly. 21 Responses to Big Headed Ground Beetle. Most are specialists in few kinds, but some, like ground beetles, eat lots of things. When handled it gives off an unpleasant scent. Butterflies, for example, sip liquid nectar from their own built-in straw, called a proboscis. What do they eat? The larvae are usually about 3/4" also and resemble the Typically run about under or on leaf litter in forests.” They are beneficial predators that are harmless to humans. Beetles are a group of insects under the order Coleoptera, the largest order of Class Insecta. Since they eat other bugs, they likely won’t come barging into your kitchen to get food. Ground beetles can be beneficial to your property by keeping the number of other bugs and pests down, they can also eat up the ones you need to make your plants and other vegetation grow. Ground beetles comprise a major portion of North American fauna.