Tartan is, of course, right with his explanation. It may be worth mentioning, however, that 'goosebumps' is an Americanism. The standard words for this skin-condition in British English - at least until relatively recently - were 'gooseflesh' or 'goose-pimples'.
I had a pet chicken when I was a child, called Mavis, who used to like to be tickled. She would lift her wing up & her skin was just the same...all covered 'chicken' bumps...then she'd close her eyes & fall off to sleep.
Yes, I had a very strange childhood.....