To care for a pet hamster, you should provide them with a suitable cage that is spacious, well-ventilated, and escape-proof. Include bedding for them to burrow in, provide a hamster wheel for exercise, and offer chew toys to keep their teeth healthy. Feed them a balanced diet of hamster food, fresh vegetables, and occasional treats. Make sure they have access to fresh water at all times. Handle them gently and regularly to socialize them. Keep their cage clean by spot cleaning daily and doing a full clean weekly. Finally, provide mental stimulation through toys and activities to keep them happy and healthy.