Mice for the most part are a minor irritation. More often than not they find their way into your house to chew on some hidden feast at night.
Rats on the other hand are a whole different ball game. They are bigger, stronger and hungrier. Native to Ireland is the brown rat and depending on its habitat it can appear brown or grey. Size, like colouration, varies depending on a number of factors. But a male can weigh as much as half a kilogramme. A female is typically smaller and lighter.