Yes hold the mice by the scruff of the neck, like a cat, look at the mouth if you see both upper and lower teeth they need to be weaned off mom. Usually mom will have another litter soon, sometimes the weanling size will still nurse and cause pinkies to die for lack of milk. If mom doesnt look like she is going to pop it would be okay to leave them in a little longer. I also look for the ears to pop up along with the teeth. Usally pinkies start fuzzing up 7-10 days after they are born... It varies with which kind of mice, fancy or swiss ,long hair or short..ect....