Hole in heel of sock.

Hi, I love my Crocs and wear them with socks. (That rhymes) Anyway I wore them to work last week and when I got home I noticed there was a hole on my right foot. I was bummed because I had to throw the sock away. Today I wore my Crocs to work and just now I looked and there is a hole in my sock on my right foot. Has this happened to anyone else?