Sleeping arrangement for toddler and infant

Hi mummies, i have a 3.5 yrs toddler and an infant. Can i check do you place them in the same room to sleep or do you separate them? Cos i noticed that my toddler will roll and say don't want sleep, want sleep. This will disturb my infant and he will become grumpy and roll constantly in his bed. Can i have your suggestion what should i do? Separate them or let them roll and roll in their beds.