What happens to fleas when a flea collar is used? - briefly
The collar continuously emits an insecticide that disperses across the animal’s skin, killing or repelling existing fleas. It also creates a lasting protective barrier that deters new fleas for several weeks.
What happens to fleas when a flea collar is used? - in detail
A flea collar releases active chemicals that spread across the animal’s skin through diffusion and limited contact. The primary compounds—typically pyrethroids such as imidacloprid, pyriproxyfen, or a combination of insect growth regulators—penetrate the sebaceous glands and coat the fur with a vapor‑like layer. Fleas that land on the host encounter the toxic agents within minutes; the neurotoxic component disrupts sodium channel function, causing rapid paralysis and death. The growth‑regulating ingredient interferes with the development of eggs and larvae, preventing the emergence of new adult fleas from any eggs that are laid.
The distribution process proceeds as follows:
- Initial release: The collar’s reservoir releases a measured dose of active ingredient every few hours.
- Diffusion: Molecules migrate outward from the collar, traveling along the neck and spreading to the back and tail base.
- Absorption: The animal’s skin absorbs a portion of the chemicals, which then circulate in the superficial lipid layer.
- Contact exposure: Fleas contacting the treated fur absorb the toxins through their exoskeleton, leading to immobilization within 30–60 minutes.
- Reproductive inhibition: Eggs laid on the host or in the environment encounter residual chemicals, reducing hatch rates by up to 95 %.
Efficacy typically lasts between 60 and 90 days, depending on the formulation and the animal’s size. Continuous exposure maintains lethal concentrations on the coat, ensuring that any newly arriving fleas are eliminated before they can establish a breeding population. Resistance development is rare with properly rotated active ingredients, but overuse of a single formulation may select for tolerant flea strains.
Safety considerations include:
- Avoiding use on animals with known sensitivity to pyrethroids.
- Monitoring for skin irritation at the collar site.
- Keeping the collar away from young children and other pets that may chew it.
In summary, the collar functions as a slow‑release delivery system that disperses insecticidal and growth‑regulating chemicals across the host’s body, delivering immediate flea kill and long‑term population suppression.