Advantage works very quickly once applied, stopping the fleas from biting in as short as three minutes. Advantage will then kill nearly one hundred percent of adult fleas in less than twelve hours and destroys eggs and larvae in around twenty short minutes. Advantage is considered to be one of the gentler flea treatments available and associated side effects are very rare. Despite its gentle nature, Advantage provides powerful and lasting protection all month long – even if your pet is out in the rain, takes frequent swims or enjoys regular baths, they will remain protected from flea bites and attacks for an entire month from one single application.