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When a customer complains of getting bitten in their home, you might have a preconceived notion as to what’s doing the biting. Or, you do a quick inspection and then dismiss the thought that there are actual pests involved at all. Do you know what you’re looking for? What are the pests that could bite people indoors?
If you’re lucky, the customer has samples of real pests. Sometimes the cause of the bites is obvious, but more often pests can’t be found, compounded by the fact that indoor bites often occur at night. Often, however, people are bitten when they’re outside (by mosquitoes, ticks, fleas, etc.) but the bites don’t show up until hours, or even days, later. The bites are then blamed on an unknown, indoor source.
Below are some of the possible causes of unidentified indoor bites. It’s useful to know whether the bites are recurring, or whether the bite was a one-time event.

Blood-feeding Biters

If the customer has a pet, the pet might have fleas. Ask if the home or the pet has been treated for fleas. Fleas stay on the animal and would only bite people under certain special circumstances, or when flea numbers are so high that the pet can no longer support the population. When fleas are biting people regularly, it’s usually when there is no longer a pet (or a wild animal host) present for the fleas to feed on. If there are enough hungry fleas already present, or emerging from pupal cases, flea bites can continue over a period of weeks.

Bed Bugs
Bed bug bites occur mainly at night, and mainly in the bedroom. They are recurring and often appear in groups of two or three bites. An inspection of the bed, frame, sheets, and nearby area should disclose whether bed bugs are a possible cause of the bites.

Bird or rodent mites can bite people under the right circumstances, although they definitely prefer to feed on their animal hosts. Bites occur most often when the bird or rodent host has been killed or has abandoned its nest, or when young birds have fledged and left the nest. Parasitic mites evacuate the abandoned nest (often in swarms) looking for new hosts. If they come in contact with people or pets, they can bite, feeding most often at night. The mites can survive for some time without a blood meal, and are more likely to die from the lower indoor humidity. Look for nest sites in or on the building. Pet gerbils and hamsters are other possible sources of parasitic mites.

Biting flies
Although mosquitoes,  flies, and biting gnats  are primarily outdoor pests, they can find their way inside and people can be bitten indoors. These bites are usually a one-time event, and the fly long gone, although mosquitoes can breed indoors in unusual circumstances involving standing water.

Miscellaneous and rare indoor blood feeders
Brown dog ticks usually stay on their dog hosts, but will bite people if a dog is not available. Body lice are rarely found in homes anymore, but can be the cause of bites in shelters and similar sites where a change of clothes is uncommon. Head lice are common but rarely leave their host’s hair and most people are aware when a family member has head lice. Biting conenose bugs can end up in homes when chickens or other farm animals have access to the house, or if there is a pack rat nest nearby.

Accidental Biters

Spiders will occasionally bite a person, but only when they are defending themselves from the prospect of being smashed. Spider bites are much less common than most people believe, and are often misdiagnosed by the medical community. Accidental spider bites occur most often at night in bed, and are single events. The actual spider is almost never apprehended.

Other insects that bite
Many of our everyday, run-of-the-mill insects are capable of biting in self defense but rarely do. Smaller insects with mandibles may attempt to defend themselves with a bite, but their jaws are not strong enough to break human skin, so a slight nip is the result. Some larger arthropods that are capable of biting and perhaps breaking the skin are cockroaches, crickets, ground beetles, centipedes, even dragonflies. Self-defense bites are single events that occur when a solitary insect gets into a bed, or when a person accidentally presses on an insect or tries to handle it.

“Invisible” Biters
Sometimes, the feeling of being bitten cannot be traced to insects or arthropods at all. The “bites” may be from a dermatological or medical condition, or the result of skin irritation from chemicals or environmental factors. There is also a psychological syndrome called delusory parasitosis where people believe that their bodies are infested by pests.


Content Courtesy of Pest Management Academy – click here for more info on Pest Management training.