Cats love to explore, especially dark, quiet places. Check inside any large appliance before closing the door. Keep screen doors and windows latched. With a little push on an unlatched door, your cat could slip outside unnoticed. Attach an identification tag and a small bell on your cat's collar.
Bones are dangerous, especially soft bones such as fish.
Bones can lodge in your cat's throat and cause choking or fatal punctures. Balls of yarn and loose string are unsafe. There is a danger of choking or strangling. Keep these things out of reach when you are not there to monitor play. Never leave a burner turned on unattended on the stove.