I have an unknown number of rats hanging in and around my coop. I have caught one rat with a (spring) rat trap with just bread as bait. I tried it again and again and tried using meat as bait and cheese but the other rats won't go near the traps. The bait is still there
Here's one of two I saw in the coop when I went down with the camera (took a few tries to catch them with the camera as I think they are camera shy):
I have thought of rat posion but I fear for my chooks
My chooks don't seem to be harmed by the rats... yet. They must be just after the feed but I am not sure how they get to it as it is hanging from the celling with a very smooth string.
Any idea what I should do?

Here's one of two I saw in the coop when I went down with the camera (took a few tries to catch them with the camera as I think they are camera shy):

I have thought of rat posion but I fear for my chooks

My chooks don't seem to be harmed by the rats... yet. They must be just after the feed but I am not sure how they get to it as it is hanging from the celling with a very smooth string.
Any idea what I should do?