There are several reasons that fleas are perceived to bite only certain people. Some individuals do not taste good, and others do not emit signals that a food source is near by. Some individuals are simply not allergic to fleabites.
Garlic is a natural flea repellent. When an individual eats a lot of garlic, fleas avoid him, because they do not like the way the person smells. In other words, people who eat garlic are not appetizing.
Each individual’s chemical makeup is different. People submit gases and skin secretions at different rates. According to sources such as the Canadian Department of Environment and Conservation, fleas tend to be attracted to people who emit high levels of carbon dioxide gas because it is a trigger to the flea that a potential blood source is in the area.
Some individuals are not aware that a flea has bitten them. Those individuals are not allergic to the saliva that the flea secretes into the bite wound to keep the blood from coagulating. The bites in those cases do not become red or itch and go unnoticed. Other individual’s are moderately allergic and perceive fewer bites than an individual who has a severe allergic reaction.