I don't know how your home is set-up, but could you use a baby monitor and go outside while the little ones are napping? Or take them all out after the morning naps are done? In summer I take them kids out twice a day, but in winter we try to get out once a day unless the weather is extreme...it really helps! I find these days that taking them all out after afternoon snack works well because then the parents pick-up from outside and you don't have to take them all back out of their snowsuits. However, ideally, outside time in the morning is great to tire them out for naptime