If bites or welts are found on the body in the morning, it is sometimes assumed to be bedbugs. Several other insects, however, also bite during the night, including mosquitoes, bat bugs, mites and fleas. Many of these bites look the same, so it's still a good idea to look for bedbugs in the mattress or other clues to figure out what caused the bites.
Most types of mosquitoes prefer to feed at dawn and dusk, but some types bite at night. Mosquitoes are more likely to feed at night if it's warm out and if mosquitoes have a way into the house, such as an open window or a torn window screen. Bedbug bites look similar to mosquito bites; both have a characteristic wheal and flare reaction.
Bat bugs are similar to bedbugs, but they only live where colonies of bats are found. Bat bugs leave once a colony of bats disperses. These bugs sometimes bite humans, but their real source of food is bats. Removing a bat infestation or sealing off the area between the bat infestation and the sleeping area eliminates bat bugs.
Mites that live on birds and rodents that nest in the building sometimes bite humans at night. Bites from mites usually cause red papules that are very itchy. Trapping rodents and discouraging birds from nesting in the air conditioning units usually eliminates a mite problem.
Fleas live on pets and bite humans in their sleep. Fleas usually leave several bites on the arms and legs. Flea bites have reddened centers, unlike bedbug bites, according to Penn State. Flea bites also tend to be smaller and harder than mosquito or bedbug bites.
Bedbugs leave bites that look like mosquito bites. If it is suspected that the bites are caused by bedbugs, take the bed apart and look for bugs in the seams of the mattress, the joints of the bed frame and underneath box springs. The bugs or the dark spots of their excrement are visible during an infestation. Adult bedbugs are flat, oval bugs about 1/4 inch long. If the bed has bedbugs, the pests are also likely going to be found in furniture and other places throughout the home.