Many Hemiptera suck plant juices although some have evolved to suck blood and body fluids. Hemiptera groups include water scorpions, water boatman, backswimmers, water striders, plant bugs, bed bugs, assassin bugs, flat bugs, seed bugs, red bugs and stink bugs. These strange flattened bugs, feed on fungus growing on the bark of trees and have the habit of dropping to the ground and disappearing in the leaf litter when disturbed. Indeed, this bug looks as it lichen is growing on its back and would be completely camouflaged against the right background.
Insects are famous for their ability to adapt and evolve to exploit every available niche.
Some beetles are even known to bore into the lead casings of telephone wiring systems.