Birds need a cage, and daily cleaning. They are great companions with little care and respond well to careful training. Small mammals tend to be clean and lively. Some, such as gerbils, hamsters, and ferrets sleep during the day and are active at night. Some may be prone to biting, and may not be a good pet for a small child.
Fish are ideal pets for busy people, and perfect for apartment living.
Their needs are limited to regular feeding and a clean tank. Pets and children seem to be meant for each other, but it's up to you to make a wise decision on what type, and when to purchase that family pet.