Why do budgies lick their mirrors?

It has to do with seeing themselves on the other side

Budgies like mirrors, I guess? When a budgie licks its mirror [especially while fluffing up its feathers, and/or seeming to almost purr] it probably considers its reflection another budgie, and so tries to preen it. I'm mostly guessing, though. My parakeet licks her mirror too. Answear- I think it is because they admire themselves

I'm not sure, but I think it is because they think their reflection is another bird. With budgies (and other birds), they normally preen their mates and also regurgitate food to them. Maybe when they lick the mirror, they are doing one of the two thinking the mirror is its mate.