This is a dangerous subject: Rats!
Bad management of bird feeding stations will always attract rats - and that is one thing that you want to discourage from your garden. Nasty, smelly disease ridden... but then on the other hand have you ever watched a young clean, cute ratlet working out how to get up onto a bird table?
Rats! More like Acrorats with their clever and well thought out moves to reach the food.
We have been plagued by birds of prey taking the young inexperienced fledglings which parents are introducing to the free meals available from those strange structures in our gardens.
I make a structure of ivy branches, without leaves, and hang the feeders inside - this at least slows down the incredible swoops of the Sparrowhawk (Accipter nisus) which used to always result in an explosion of tiny feathers... however, enter the law of the double edged sword!
A young ratlet had worked out that the fine strong branches of the ivy provided a great climbing frame for an acrobatic rat to reach the feeders - more time wasting for my wife and I as we watch with a "Will he - won't he?" conversation going to-and-fro.
He did make it to the feeder, but has now vanished and we think that nature's balance has taken its toll - the Sparrowhawk looks well fed, and they are very keen on young rat... although 98% of their diet is other birds.