Rats are intelligent, acrobatic creatures that can multiply at alarming rates. They will often find their way into homes to breed and to find safety from predators.
If you look closely at the top of this water heater, you will notice an uninvited guest. Norway rats are quite large and have long tails. They need to continually gnaw on whatever they can find to keep their teeth at the proper length for eating. This can mean lots of damage to stored items, not just food. An experienced professional can determine how they are getting in and help you take back control of your home.