Mating plug

[3][4] While females can expel the plugs afterwards, the male's sperm still gets a time advantage in getting to the egg, which is often the deciding factor in fertilization.

Mating plugs are used by many species, including several primates,[8][6][9] kangaroos,[10][11][12] bees,[13] reptiles,[14] rodents,[15][16][17][18] scorpions,[19] bats,[20][21] and spiders.

[23] For example, to protect their paternity, male variable checkerspot butterflies pass a mating plug into the genital opening of females to prevent them from remating.

[24] The Heliconius charithonia butterfly uses a mating plug in the form of a spermatophore that provides predatory defense chemicals and protein sources for developing eggs.

[30] In Thamnophis sirtalis parietalis, commonly known as red-sided garter snakes, males deposit a gelatinous copulatory plug to seal female snake's cloacal opening to prevent re-mating, leakage of the deposited sperm, and alters female pheromonal cues that attract mates.