rats need a source of food and somewhere to breed piles of junk wooden decking attract rats like a magnet tidy up as best you can trap as many as you can and remove the food supply then finish the rest with terriers and a smoker lastly when rats are gone put down the poisson you can get some in little bags which you put underground away from pets and any new rats get killed before they can breed hope this helps ps everybody gets rats sometimes good luck steve