Keep pets off your laptop.
You might find it funny when your favorite cat climbs onto your laptop to "help" you work, but don’t encourage this behavior. Cats are attracted to the warmth of the working device, but don’t allow your cat to sit there because their fur can get into the system’s fans. This may eventually lead to overheating and ruin its work.
Don’t eat in front of your computer either. Any bits of food that fall into your keyboard will eventually attract the most unwanted guests: cockroaches and ants.