A study suggests twin infants are happier and healthier sleeping together, reports CBC News.

The infants became stronger, having more time to rest and spending less time crying, which also helped parents, she said.

“While that one’s awake, the other’s asleep. When do you get your rest? Having them awake at the same time is really important,” Hayward said.

“You’ll actually have an opportunity to rest and do those things you need to do.”