Bug

Bug may refer to:
* Bug (defect), a computer or hardware defect found in a device that needs fixing
* Bug (device), a type of covert listening device
* Bug (illness), a colloquial term for an illness caused by a virus or other microorganism
* Bug (invertebrate), a colloquial term for any insect, arachnid, or other terrestrial arthropod that is a pest
** Insect, what "bug" often seems to refer to