How does a flea collar kill fleas? - briefly
A flea collar emits insecticidal vapors that settle on the animal’s skin and are absorbed, disrupting the fleas’ nervous system and causing swift mortality. The active agents, often pyrethroids or organophosphates, remain effective for several weeks, delivering continuous protection.
How does a flea collar kill fleas? - in detail
Flea collars contain a polymer matrix impregnated with one or more insecticidal compounds. The matrix releases the active agents as a low‑volume vapor that spreads across the animal’s skin and coat. Continuous diffusion maintains a relatively constant concentration of the chemicals in the immediate environment of the animal.
The primary insecticide commonly employed is a neonicotinoid such as imidacloprid. Neonicotinoids bind to nicotinic acetylcholine receptors in the flea’s nervous system, causing persistent excitation, paralysis, and death. Some collars also incorporate a growth‑regulating agent like pyriproxyfen, which mimics juvenile hormone and prevents larvae from developing into adults.
Release is achieved through:
- Molecular diffusion from the polymer core to the surface;
- Evaporation of volatile fractions into the surrounding air;
- Direct contact transfer when the animal’s fur rubs against the collar material.
Fleas encounter the chemicals in three ways:
- Contact with the vaporized insecticide while moving across the animal’s body;
- Grooming‑induced ingestion of residue deposited on the fur;
- Exposure to the growth regulator during the larval stage in the environment surrounding the host.
The combined effect eliminates adult fleas rapidly and suppresses the emergence of new adults, breaking the life cycle. Concentrations are calibrated to be lethal to arthropods while remaining below toxic thresholds for mammals, reducing the risk of systemic absorption.
Proper usage requires the collar to remain on the animal for the manufacturer‑specified duration, typically eight weeks, to ensure sustained release and complete cycle interruption. Replacement after the effective period restores the protective vapor pressure and prevents resurgence of infestation.