RATS

My back garden is overrun with rats. Over the winter they made their home in my summerhouse.
Ive not been able to use it yet as the stench of rat droppings that were covering every surface, was eye wateringly pungent.
it took me several days to clear the area from droppings and general mess from the rats who had made nests and reared families in there. I put rat poison blocks down first of all in the hope of killing them off. When I was sure the blocks were no longer being taken I began the clean up.As I was cleaning they literally ran over my foot as the made their escape.
Finally I was able to scour the place and wash it out with jeyes fluid. I blocked up the rat holes and repaired as much of the chewed damage as I could. I think my summerhouse is now rat free.
However, the little blighters are now running riot in the garden.
The council came out and set traps etc but the rats are going nowhere.

I know it is an on-going battle and we will never be free of them. The rats infestation is not helped by people who dont seem to know how to use dustbins and prefer to throw their rubbish in the back streets.

Does anyone know of any methods for keeping the numbers down? I am at my wits end over this.