Dolly and the hedgehog wheels

I've been meaning to take a picture of these for a while, but haven't had the chance to stop. I managed to grab a quick shot today when I had to make a turn, the perfect opportunity. Im not entirely sure what they're meant to be, there wasn't a sign, but I find them quite cute.

I'm so confused this week because I swapped work days, I honestly can't figure out what day it is at all. I suspect it will take a few weeks before I get my new schedule in my head, Easter doesn't help much either.