Eastern Spadefoot frogs dig getting down in the rain:
To avoid predators such as fish, they evolved to consummate their vows in temporary ponds created by heavy rainstorms. “It’s one night of a massive frog orgy,” says [herpetology professor Steve] Johnson. When the downpour starts, male toads emerge from the ground making “vomiting-like” mating calls. The females respond, and the orgy runs through the night, after which the females lay thousands of fertilized eggs in the ponds. Most other toads spend a long time looking for mates, Johnson says, so this behavior is quite unique.
Within a few days, tadpoles hatch in such high numbers that the ponds resemble “boiling water” or a “super-organism that’s moving,” Johnson says. The ponds grow algae the tadpoles feed on. Two weeks after the rainy night, tadpoles become toads, hop away from their birthplaces, and burrow into the ground where they await their turn to party. Johnson says the toads are patient and can wait for the perfect mating conditions for months or years.