Fleas

Fleas

Adult Male Cat flea
an adult male cat flea, by Jim Kalisch, UNL

Fleas are obligate blood feeders. This means the female flea must have a blood meal to reproduce. The female flea lays eggs while on the animal host, but since the eggs are not glued to hair, they fall off the host into the nesting material. Flea eggs hatch into tiny wormlike larvae that feed on organic debris.

Fleas are nearly always associated with animals that nest. Cats, dogs, raccoons, opossum, rabbits, rats, and mice are nesting animals and commonly have fleas, but grazing animals like cattle, deer, and elk rarely do.

Controlling FleasFlea control is complicated and includes treating the following:

  • pet
  • home environment, particularly pet bedding areas
  • outdoor areas, where pets spend time
  • Each of these different areas requires a specific type of treatment.

Treat the animal. There are a number of methods for treating pets. Dips and shampoos can be obtained from a pet store or a veterinarian. Some of the more common prescription products include lufenuron (Program), fipronil (Frontline Top Spot), or imidacloprid (Advantage). Preventative treatments should be started in the springtime before flea infestations increase. In the case of a wild animal host, it is important to exclude the wild animal as the source of the fleas.

Treat the home environment.Places where pets spend time are most likely infested with fleas. Vacuum thoroughly where pets spend time resting. Consider steam-cleaning carpets to help remove food for larvae; this may even kill larvae. Beds that pets sleep on will likely be infested. Wash bedding in hot water and dry in a hot dryer. Pay special attention to where pets jump off the bed or sofa. These are areas where flea eggs could be dislodged from the pet.

Chemical treatments - Using an Insect Growth Regulator (IGR) will control immature stages, but an adulticide may be necessary to control the adult biting stage. If attempting to do this yourself, purchase combination products containing methoprene (PreCor), pyriproxifen (Archer, Nylar), and a pyrethroid (permethrin or bifenthrin are examples).

Treat outdoors, especially shady areas. Again, use an IGR in the landscape, particularly in shady areas, where flea larvae are most likely to be found. Products containing pyriproxifen (Archer or Nylar) are more stable in UV light, and will last longer outdoors.

Fleas can be puzzling pests that may take some detective work in discovering the source of an infestation. Here are some examples.

Case #1: The living room of an older home was infested with fleas, but the family had no pets. How is this possible?

Answer: A female raccoon climbed up downspouts to get onto the roof. She crawled into an older, unused chimney and produced a litter of young. Flea eggs dropped to the bottom of the chimney, producing larvae and adult fleas. How common are fleas on raccoons? Results of one research study showed cat fleas were found on 50% of the trapped raccoons. A single raccoon can carry more than 50 fleas.

Case #2: Flea larvae were found in the bed of a pre-schooler. The pet cat sleeps on the bed and was found to be infested. This pet cat never goes outdoors. How could this flea infestation get started?

Answer: One of the parents visited a family who had animals and picked up a flea on clothing. Fleas have remarkable jumping abilities and can easily hitch a ride home.

flea larvae
flea larvae with the point of a stick pin for size comparison, photo by Barb Ogg
Barb Ogg
Emeritus Extension Educator, Entomology
Barb Ogg shared her love of entomology with clientele throughout Nebraska for many years through Nebraska Extension. Barb retired in 2015.

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