pest

n.

1. Anything destructive

   virus, germ, insect pest, bug, harmful bird, bird of prey, destructive animal; see also disease, insect.

   Common pests include: house fly, mosquito, flea, louse, mite, chigger, bedbug, ant, silverfish, earwig, mealybug, cricket, grub, cockroach, termite, carpenter ant, fire ant, centipede, millipede, tick, botfly, screw-worm fly, leaf hopper, aphid, codling moth, peachtree borer, Japanese beetle, Colorado beetle, grain beetle, corn borer, boll weevil, San Jose scale, oyster shell scale, squash bug, peach moth, gypsy moth, hawk moth, wasp, wireworm, cutworm, tent caterpillar, plum curculio, pear slug, tomato slug, mouse, rat, gopher, prairie dog, woodchuck, groundhog, rabbit, mole, weasel, coyote, hawk.

2. A nuisance

   bother, vexation, thorn in the side, annoyance; see trouble 2.