any ideas on getting rid of rats in your garden.

Aside from the usual traps and poisons, you need to ask why they are there
in the first place or they will just come back again? Is there a lot of
rubbish in the vicinity? Any food lying around, perhaps scattered from a
bird table? Does a neighbour throw out bread for the birds? Do you put meat
into a compost bin - apparently this attracts them.
Are there good places for them to hide and set up nests?

--
David
.... Email address on website http://www.avisoft.co.uk