I can remember us hitting a dirty great bat at Falconara on lift-off in a Belfast one evening just as the sun was going down. When we got back to Brize, the Station Flight Safety Officer asked my captain (who could be an awkward sod at times) to fill in a Birdstrike Report. It was pointed out that a bat is a mammal and therefore, not a bird. SFSO was told that if he supplied a Batstrike Form then it would be filled in. The stand-off went on for weeks.