Older children babysitting younger siblings

I have 8 children ranging from 0-17. I work at 8:00am-3:30pm. My husband usually sleeps all day and goes to work from 6pm-7am. The youngest 3 stay at home with him, or go to their grandparents. This spring break all the kids have been staying home, and watching eachother while my husband sleeps all day. Is it wrong for me to expect them to watch eachother?