Many weevils are damaging to crops. The grain or wheat weevil (Sitophilus granarius) damages stored grain. The boll weevil (Anthonomus grandis) attacks cotton crops. It lays its eggs inside unripe cotton bolls, and the young weevils eat their way out.
Weevils are often found in dry foods including nuts and seeds, cereal and grain products. In the domestic setting, they are most likely to be observed when a bag of flour is opened, although they will happily infest most types of grain including oats, barley and breakfast cereals. Their presence is often indicated by the granules of the infested item sticking together in strings, as if caught in a cobweb. If ingested, E. coli infection and other various diseases can be contracted from weevils, depending on their diet.