Snake Breeding Ball
Male watersnakes (of the genus Nerodia, for example) may detect a female ready to breed by picking up on her pheromone trail. If there are many males in the swamp, they may converge on the female at the same time. There is a huge incentive for being the first male to breed, not only does the male secure a good chance his sperm will fertilize the female’s eggs, but male watersnakes of some species are known to deposit a plug in a female’s cloaca that temporarily prohibits other males from inserting their hemipenes (a male snake’s reproductive organs). So, with this in mind, the males writhe all over each other (and the female) attempting to be the first to maneuver into position, resulting in a snake breeding ball.
There are other ways for males to compete for females in the animal kingdom. One method is by defending a territory from other males, securing the right to breed with nearby females. Another technique is to impress a female with elaborate displays. But for male Cottonmouths, the way they secure breeding rights to a female is one that may be familiar to anyone that has spent a lot of late nights in the local bar. That is to say, when two male Cottonmouths have their eye on the same female, they will simply fight over her.