Optimal weight for your cat is its weight at one year of age unless it was already obese. The best time to introduce dogs and cats is when puppies are under 12 weeks of age and kittens are under 7 weeks of age. In time they may ignore each other or may even learn to play together. Mixing fast swimmers or stronger kinds of goldfish with slower, weaker ones is a bad idea. The slower fish will not get enough to eat and the others will be overfed.
Hamsters are nocturnal animals, which means they are active at night.
The best time to clean the cage or exercise the hamster is in the evening or early morning. Remember to keep the cage away from drafts and direct sunlight. Rabbits do not sweat, so it is best if you don't hold them for long periods. Rabbits will scratch or squirm when they are tired of being held. If your rabbit starts squirming and you are losing your hold, drop to one knee so should it can get away from you.