A pensioner helped scientists document the first ever “contactless” sex of mammals (2 photos + 1 video)
Bats of the species Eptesicus serotinus have very large genitals, and now scientists have become clear why. 
Males of the bat species Eptesicus serotinus have huge genitals. Even though these are fairly large representatives of bats (with a wingspan of more than 35 centimeters), their penis is still considered abnormally large. It is seven times the size of the female genitals, and its shape makes penetration impossible. For several decades, scientists have puzzled over why nature created such huge genital organs if they cannot be used for their intended purpose. 
Suddenly, a pensioner from Jan Juken from the village of Kasternei in the Netherlands helped solve this riddle. The man became seriously interested in watching bats and installed several cameras on the feeders to monitor their personal lives. One of the videos showed exactly how leatherbacks reproduce.
It turns out that this species of bat mates without penetration. They are limited to simply contact of the genitals. A similar method of sex is common among birds, but has never before been observed in mammals.
Scientists have suggested that females are able to retain the sperm of males for 2-4 months in order to choose from whom to have offspring.
The results of the study were published in the scientific journal Current Biology.
