Rats are present in almost all habitats in Ireland. This generally isn’t a problem until they come close to houses and people. Sometimes rats are attracted to gardens where birds are being fed, so the key to stopping this is to remove what’s attracting them! What’s attracting them is the food, but more specifically the food on the ground. If you can stop your food spillage problem, you’ll stop your rat problem.
Solutions include switching to foods that don’t spill as much (e.g. peanuts), using bird tables where food is out of reach from the ground, or using hanging bird feeders that catch any food that might otherwise be spilled. You can get creative with this by attaching a plastic plate to the base of your feeder to catch any falling seed.
If your feeders are over hard ground its worthwhile cleaning up any spillage on a daily basis too.