Rat infestations can be a real pain. They chew their way into and out of food containers, wee and poo everywhere and spread 35 diseases to humans. In 2009 a study showed that rats caused over 9 billion dollars worth of damage a year, in the US alone! This is despite all the trapping, repellents, poisons and deterrents known to mankind. There is no evidence that these have made any difference.

So what can you do to deal with a rat infestation?

There are a few things you can try but many people find it can be very difficult to keep a determined rat out.

Block holes. An adult rat can squeeze through a space only 2cm wide so it can be very difficult to block all the holes they might fit through. A large building could have any number of holes. Some of these may be inaccessible to humans making some of the holes impossible to block. The cost could be very high and guess what; miss a hole and the rats are bound to find it.
Rat repellent flooring. This unusual device from Hammer Technologies allows you to keep rats away in a completely new way. It's rat-deterrent flooring which gets rid of rats, keeping your stuff safe. It works in a way like no other rat repellent. It is safe and non-toxic, unlike nasty poisons which can harm animals other than those you are trying to get rid of.
Water. Eliminate water sources so rats have no easy-to-find drinking water. They can go without water longer than a camel but if there's no water about it's one less reason for them to stay. Don't leave your pets drinking bowls out over night. Let your dog have a drink and then put the bowl away.
Deterrents. Sound deterrent devices often don't work terribly well. They emit a high frequency sound only the rats can hear. They find it unpleasant and leave, although they often don't keep determined rats away. There is little evidence that these make a significant difference.