Anti-rat protection

Rats only need a small tiny slit to get through... I truly think that it is a lost cause trying to protect compost bins on a whole site as they live wherever there is a small nook or cranny that they can hide in or make a house. Traps and Bait is the only way to keep a bit of control of them.

Or you could use one of our "patented" African style rat traps as per the photo of one of mine on my plot...

Simples.. Dig a hole, place plastic fertilizer bucket about 3/4 below ground level, fit a wire hoop over the bucket with a sweetcorn cob drilled to act as a roller on the wire.. Bait the cob with some peanut butter and fill the bucket to about 1/3 depth.

Rat comes to the trap and falls off the roller and into the water.... and they cant swim.. You will catch loads.. Dot them all around the site and you could feed the lions in a zoo!! (Oh and I'll take 5p per rat caught) 

Rats swim very well , on the surface and underwater ! That is why they thrive in sewers !
So they do not have a quick death in a water filled bucket.
I would use a bigger dry bucket and kill the rat with a stick (fast and not difficult) also you can release anything that you did not intend to catch.
Death by drowning in your current trap may not be any worse than polsonlng but i would personally favour a faster killing trap.

Rats need access to drinking water every day. It's sometimes easier to restrict access to water then access to food. If there is no water they will move away.

   Not easy to restrict what comes down from the sky !

The rats would wait a long time for your part of the country to dry out this year !

4 slabs with a 1cm gap between them, plenty of worms and no rats

I guess the rats get into the compost bins for 1 or both of 2 reasons; they are there for food or to have a place to sleep/breed. The first you could make less attractive by not composting kitchen waste on the site, the second by regular disturbance. I don't think chicken wire would be so bad. Although they may be able to bite through it, I think it would take them considerable time and energy. If there is no chicken meat or something like it to attract them, I don't think they would bother.

As with many things, try to think why they are there as it is better to prevent them coming than to lure them in and then kill them.

Best wishes,

Maarten