Fleas are a common pest that can bite humans, causing a mild reaction for most people; however, some people can suffer an allergic reaction to the flea's saliva. Flea bites can also remain itchy for several weeks. Fleas can also carry diseases which are transferred when the host is bitten, the most well-known being the bubonic plague. Outbreaks of bubonic plague are much rarer, although they still occur, due to better living conditions. Flea pest control includes direct treatment of the infected pet along with use of specialized insecticides to ensure complete elimination of the flea infestation in the house.