Bringing a puppy home is a significant adjustment for both the human and the puppy. Especially in the first few weeks, the separation anxiety for the little dog can be quite intense. The lovingly designed toys feature an opening to insert a heartbeat simulator (sold separately). This device produces an artificial heartbeat, mimicking the familiar sounds of the mother's heartbeat or that of littermates. This has a calming effect on the puppy and helps it fall asleep. Additionally, the soft material allows the puppy to snuggle gently with its toy and feel secure. The battery-operated sound chip emits a heartbeat for about 10 minutes after being turned on, before the toy automatically shuts off. The battery is protected by a plastic strip that must be removed before use. Caution: The simulator should only be used in conjunction with the cuddly toy.