When you have two little kids close in age do they share underware?

I have two little girls who are 18 months apart in age, yet are nearly identical in size. They share shirts and pajamas, but have their own pants. I buy a lot of socks and undies, so it's not like they are grungy or anything, but I don't see a need to seperate them per girl. Is this what you do too? Or do you individualize the personals stuff? I just have a big basket in the bathroom with socks and undies (another of jamies) so when they get out of the bath they pick out their own. Your answer probably won't cnahge anything :) but I'm curious.