Bed bug bites may resemble mosquito bites and usually appear in groups. The bites will often be itchy like mosquito bites. It is nearly impossible to tell a mosquito bite from a bed bug bite unless you control the environment and rule out mosquitoes as a possibility. This is why the mere presence of bites is not solid bed bug evidence

While the unsuspecting human is relaxing on their chair, couch, or mattress, the bed bug seeks to suck their blood. After the bed bug is done feeding, they will retreat to digest and lay eggs. The bed bug bites will sometimes continue to bleed for a moment once the bed bug has finished, leaving a small blood stain on bed linens or clothing.

The victim will not usually feel the bed bug bites because they inject an analgesic substance. Like other bloodsuckers, bed bugs use an anticoagulant to prevent the blood from clotting. Evidence of bed bug bites on the skin may not appear immediately, or may not appear at all.

Some people will have an allergic reaction to the bite (to the anticoagulant). A bad reaction to a bed bug bite can include redness and swelling. The most severe reaction to a bed bug bite can include anaphylaxis. Though the bites don’t usually cause physical health problems, the presence of bed bugs can cause anxiety, insomnia, and paranoia. https://www.wikihow.com/Treat-Bed-Bug-Bites