Springtails

Lately, after heavy overnight rain, any containers in the garden that can hold water have hundreds, and sometimes thousands, of springtails floating on the surface film by daybreak. It seems likely that they were feeding and breeding on organic matter and probably fungi in the bottom of the containers when they had dried out, then have become marooned on the rising water. 

They float in rafts of up to one thousand individuals. I think there is more than one species involved, but I'm struggling to identify them with certainty. 

The two movies at the bottom of this post show just how active they are, many of them using their furcula under their tail to leap into the air.