Hoppers can most certainly give a bite, and don't usually hesitate to do so. Rule of thumb, if it has its eyes open, you don't want to leave it unattended with your snake. By the sounds of it, you had a fuzzy. I've never known a hopper to be squirmy, but rather popping around the cage like a piece of popcorn. I swear it takes me as long to clean two small mouse cages as it does to clean 10 large tubs of rats, friggin mice are springing all over the place