To keep your WhyPet healthy and happy, you need to feed it and play with it regularly.
You can play with your pet any time in any chat room. A fun place to play is the Pets Park, specially built for pet owners. Chat "summon pet" to call your WhyPet, if you have one (or your last purchased pet if you have many). Or, chat "summon pet" and the pet's name to call a specific pet. When you're done playing, chat "dismiss pet" to send it home.
You may notice that from time to time your WhyPet displays a speech bubble in chat. This bubble appears when the WhyPet needs something: food, sleep, play time, or just to go home. Try to respond to these bubbles as best you can to keep your pet happy.
Pets get hungry if they're not fed every day, and could cry or even refuse to listen to you. Make sure to feed your WhyPet every day so it stays healthy.
To buy food for your pet, click on the food bag in the Pet Store. You can get to the Pet Store from the link on the WhyPets Page, or the Destination Menu. Food can only be purchased with Pearls. You can feed your pet in a chat room by chatting the name of your pet followed by "feed". You can also feed your pet by going to its Certificate Page and clicking the "Feed Pet" button.
If you aren't sure you'll be able to come to Whyville for a while, you can set up auto feed to feed your pet while you're away. Auto Feed gives your pet food every day. Just make sure you have enough food before turning on this option or you might run out.