It’s better to hang the mobile on a cot in a way that the bottom hands are approximately 16 inches above the surface of the crib mattress. You can give some time to your baby to develop his interest. However, if he seems uninterested, you can lower it a little. Here the key is to make sure that the kid can reach it easily. But also make sure that the strings don’t dangle below the crib rails. Such a position is ideal for keeping the musical mobile hanging above the cot.