I love flying foxes, so cute XD They're one of the things I spent most time studying when trying to work out how to attach wings to a human :) Didn't realise they could echolocate at all, but I've only ever seem them during the day so figured they just used their eyes. The idea that maybe they evolved away from it with the size is an interesting one. The smaller bats I'm familiar with gad about at night and hunt insects and small rodents so the echolocation is probably more useful there.