Fruit bat has tongue, can use it. Image Oregon Zoo
I read about bat fellatio on The Thoughtful Animal when the paper about it by Tan et al. first came out earlier this year. So I was really excited when I saw it for myself at the Oregon Zoo just a few weeks ago:
Now the original paper has won the Ig Nobel prize in Biology!
Interestingly, the bats that I recorded were a different species of fruit bat (straw-colored fruit bat Eidolon helvum) than the original paper described (short-nosed fruit bat Cynopterus sphinx).
Bats practice fellatio during sex (which seems to prolong intercourse) and also lick their genitals after sex (potentially to protect against STDs due to the antibiotic properties of saliva). You can see both happening in the video.
Tan, M., Jones, G., Zhu, G., Ye, J., Hong, T., Zhou, S., Zhang, S., and Zhang, L. 2010. Fellatio by Fruit Bats Prolongs Copulation Time. PLoS ONE, 4 (10): e7595. Link