Is it normal that i sometimes lick my own socks at night

Sometimes when I can't fall asleep, I get really bored. Then I just start taking some of my old dirty socks and licking them. I hardly even notice, but I can't help it. It gets me high of the flavours I encounter on the fabric but I know it's kinda strange
Like if, for example, I stepped on cheese that day it might have a cheesey hint to it or if I stepped on grass then a fresh grassy flavour.
it's just something I do to help myself fall asleep, but lately I've started dreaming about socks and craving them during the day. sometimes I ask to go to the bathroom in class...when really I'm in the stall with my socks off, licking them. My dad almost walked in on me sock-licking the other night but luckily I hid them in time. It's just that I'm starting to feel like this isn't a normal habit, and it's getting a little out of hand. Is it?