Sleeping at other people's houses

Nicole

I have gone back to work 3 days a week. And my sister and mom are watching my son but he refuses to sleep in their pack n play at their houses. I was wondering if anyone have any suggestions of how to get him to nap at other places? When we are home he will take an 2-3 hour nap in the morning and about 2 hour nap in the afternoon. When hes at other houses only like 20-30 mins at time.