Due to my chicks being confined to their run and coop because of the avian flu issue and having to put food in there, I now have a rat problem ! I can see various ratholes. What is the best solution, never had any problems when they were free ranging.
Ideally you would have a run that rats can't get into, but that may be a lot of work for you. You certainly can't use poison and they wouldn't eat it in preference to chicken feed anyway. First thing is to remove the feed at night and make sure they haven't access to water. They will eat the spilled pellets, but need water as well. With no feed in the run at night you could then bait cage traps with chicken feed outside the run. I don't like snap traps because you may well have hedgehogs moving around there. You will need to humanly kill any rats caught, so drowning isn't permitted. A single shot with an air pistol is acceptable I think?
A cage trap is best in your situation, our neighbour uses them around the cattle sheds, and they then shoot the rats.
They did use rat snap traps, but they had two rats that just caught by the tail and were running around with the traps. At least you could hear the rat approaching.
We have a mouse invasion locally. The local owls and kestrels are having a field day
I don't know about chicks, but with adult birds a treadle feeder is a good option (though my hens took a lot of persuading to use it when it first arrived...). The downside is that it doesn't offer the entertainment value of having to actively search for food, so they get bored.