Provide name of businesses whose category is pets and are still opened after 9PM.
category refers to category_name; open after 9pm refers to closing_time > '9PM';
SELECT T3.business_id FROM Categories AS T1 INNER JOIN Business_Categories AS T2 ON T1.category_id = T2.category_id INNER JOIN Business AS T3 ON T2.business_id = T3.business_id INNER JOIN Business_Hours AS T4 ON T3.business_id = T4.business_id WHERE T4.closing_time > '9PM' AND T1.category_name LIKE 'Pets'