Pests like mice, rats, birds, and insects damage and reduce crop yields. A pest is any organism that spreads disease, causes destruction, or is a nuisance. There are several types of pests including insects, arthropods, weeds, mollusks, and microbial organisms. Common crop pests include aphids, beetles, grasshoppers, whiteflies, caterpillars, weevils, bugs, moths, and ladybirds. Pesticides are poisons used to kill pests that harm plants and animals. They come in different containers and formulations.