A definitive diagnosis of health effects due to bed bugs requires a search for and finding of the insect in the sleeping environment as symptoms are not sufficiently specific. Bed bugs classically form a line of bites colloquially referred to as "breakfast, lunch, and dinner" and rarely feed in the armpit or behind the knee which may help differentiate it from other biting insects. If the number in a house is large a pungent sweet odor may be described. There are specially trained dogs that can detect this smell.
Individual responses to bites vary, ranging from no visible effect (in about 20–70%), to small macular spots, to prominent wheals and bullae formations along with intense itching that may last several days. The bites often occur in a line. A central spot of bleeding may also occur due to the release of anticoagulants in the bug's saliva.
Another solution you hear about is vacuuming. You can vacuum up a lot of insects, but eggs are harder to get, and vacuuming won't in and of itself kill bed bugs. Indeed, vacuuming can end up spreading bed bugs to other rooms—when emptying the canister, for example. Pest control operators who use vacuums take measures to prevent bed bugs from escaping when the vacuum is emptied.
Bed bugs are small, brownish, flattened insects that feed solely on the blood of animals. Although the common bed bug (Cimex lectularius) prefers feeding on humans, it will also bite other warm-blooded animals, including dogs, cats, birds and rodents. It has done so since ancient times; bed bugs are mentioned in medieval European texts and classical Greek writings back to the time of Aristotle.
One bed bug will usually take more than one bite. Once a bed bug inserts its mouthparts and finds a suitable blood vessel, it will begin feeding. However, finding the right blood vessel may take more than one injection into the skin. In addition, bed bugs are very sensitive to movement by the host they are feeding on. Therefore, if a sleeping person moves, a feeding bed bug will probably withdraw its mouthparts and begin its search for a blood meal on another part of the body. It’s important to remember that the number of bites a person receives is not indicative of the number of bed bugs that feed on that person.