Fleas are small, wingless insects that survive as ectoparasites, meaning they live on the outside of a host and feed on blood. The question of whether these pests bite more at night is a common one for people dealing with an infestation. Understanding flea behavior requires moving past the concept of a strict nightly schedule and focusing instead on the biological drives that govern when and why they seek a blood meal.
Flea Feeding Patterns and Host Cues
Fleas do not adhere to a strictly nocturnal or diurnal feeding schedule; they feed continuously whenever a host is available. Their activity is heavily influenced by host presence, rather than the solar cycle. While some studies show locomotive activity may peak around sunset, feeding is driven primarily by sensory detection of a nearby animal.
A flea’s primary method for locating a host involves sensing specific environmental cues. They detect body heat, movement, and the exhaled carbon dioxide produced by a potential blood source. The perception that biting increases at night often occurs because the human host is stationary for a long period while sleeping. This prolonged stillness provides an ideal, undisturbed feeding opportunity for the fleas, allowing multiple bites to accumulate unnoticed.
Adult fleas are continuous feeders, requiring a blood meal multiple times per day to survive and reproduce. Female fleas begin laying eggs within 24 to 48 hours of their first blood meal. They will readily feed at any time the host is accessible, including periods of rest. The pupae stage is also stimulated to hatch by the physical vibrations and carbon dioxide of a resting host, further contributing to the appearance of increased nocturnal activity.
Identifying Common Flea Bites
Flea bites present with distinct physical characteristics that help confirm an infestation. The bites typically appear as small, raised, red bumps, often featuring a small, darker red spot at the center. Unlike single, scattered mosquito bites, flea bites frequently appear in clusters or linear groupings of two or three.
This clustered pattern is sometimes referred to as “breakfast, lunch, and dinner,” as a flea may bite several times in the same general area before moving on. Fleas typically target the lower extremities, which is the closest accessible area when they jump from the floor or carpet. Bites are most common around the ankles, feet, and lower legs, but can also be found on the waist or in areas where clothing is tight.
Understanding Flea Habitats
The majority of a flea population does not reside on the host but rather in the surrounding environment. Adult fleas live on the host to feed, but they deposit eggs that are not sticky and quickly fall off into the environment. This means that the home and yard serve as the primary reservoir for the infestation.
The flea life cycle includes four stages: egg, larva, pupa, and adult. The eggs, larvae, and pupae are typically found hidden within carpets, upholstered furniture, pet bedding, and cracks in the flooring. Flea larvae are blind and actively avoid light, preferring to inhabit dark, protected areas where they feed on organic debris, including “flea dirt” (feces from adult fleas). Outdoors, fleas thrive in shaded, moist areas like under shrubs, in tall grass, or in leaf litter, where their immature stages can survive until they mature.
Immediate Steps for Infestation Control
Controlling a flea infestation requires a simultaneous, multi-pronged approach that treats both the host and the environment. One of the first steps involves treating any pets in the home with a veterinarian-approved flea preventative, which is necessary to break the reproductive cycle. Without treating the animal host, the adult fleas will continue to feed and lay eggs, perpetuating the problem.
Aggressive environmental cleaning is also necessary to eliminate the immature life stages residing off the host. This includes frequent and thorough vacuuming of all carpets, rugs, and furniture. The vacuum bag or canister contents must be sealed and disposed of immediately outdoors after use. The vibration from the vacuum cleaner is also beneficial because it can stimulate dormant pupae to hatch, making them susceptible to immediate removal or subsequent treatments.
All bedding, including pet beds and linens, should be washed in hot, soapy water, ideally at 130 degrees Fahrenheit or higher. Drying these items on the highest heat setting is effective at killing all flea life stages. For the yard, trimming overgrown shrubs and removing leaf litter reduces the shady, moist areas where outdoor fleas breed, making the area less hospitable.