effect (in about 20–70%), to small flat (macular) spots, to the formation of prominent blisters (wheals and bullae) along with intense itching that may last several days. Vesicles and nodules may also form. The lesions due to bites may become secondarily infected due to scratching but systemic effects from bed bug bites are very rare. A central spot of bleeding may also occur due to the release of blood thinning substances in the bug's saliva. Symptoms may not appear until some days after the bites have occurred. Reactions often become brisker after multiple bites due to possible sensitization to the salivary proteins of the bed bug. Numerous bites may lead to a red rash or hives. Psychological Serious infestations and chronic attacks can cause anxiety, stress, and sleep difficulties. Development of refractory delusional parasitosis is possible, as a person develops an overwhelming obsession with bed bugs. Other A number of other symptoms may occur from either the bite of the bed bugs or from their exposure. Serious allergic reactions including anaphylaxis from the injection of serum and other nonspecific proteins have been rarely documented. Due to each bite taking a tiny amount of blood, the chronic or severe infestation may lead to anemia. Bacterial skin infection may occur due to skin breakdown from scratching. Systemic poisoning may occur if the bites are numerous. Exposure to bed bugs may trigger an asthma attack via the effects of airborne allergens although evidence of this association is limited. There is no evidence that bed bugs transmit infectious diseases even though they appear physically capable of carrying pathogens and this possibility has been investigated. The bite itself may be painful thus resulting in poor sleep and worse work performance. Bed bugs can feed on warm-blooded animals other than humans, such as pets. The signs left by the bites are the same as in the case of people and cause identical symptoms (skin irritation, scratching etc.). Bed bugs can infest poultry sheds and cause anemia and a decrease in egg production in hens. Insect Bed bug infestations are primarily the result of two species of insects from genus Cimex: Cimex lectularius (the common bed bug) and Cimex hemipterus (the tropical bed bug). These insects feed exclusively on blood and, at any stage of development, may survive up to 70 days without feeding. Adult Cimex are light brown to reddish-brown, flat, oval, and have no hind