Shy Piggy!
My daughter and I call the guinea pigs´ need to run EVEN when you are trying to bribe them with a treat "The Code of the Cavies". You see, guinea pigs are actually organized and bound by that code to run or, at least, be uncooperative when you try to pick them up.
I think there are severe penalties for gps that violate this code, so be careful about posting their names...
I think there are severe penalties for gps that violate this code, so be careful about posting their names...