Problem with poisoned rats disposed of in compost.

Hi everyone I've only just found out how to post a question as it's been such a long time LOL. I'm useless ha ha.

I think I did a very stupid thing months and months ago. I had a huge problem with rats around my hen house. I tried all sorts of ways to get them to move away but had to resort to poison in the end. I managed to get rid of them at least I don't have a problem now. BUT I picked up 2 dead ones literally a day after we put the poison down and I then didn't know what to do with them. I didn't dare bury them for fear my cats or foxes etc would dig them up, so I put them in my plastic Darlek compost bin then just kept adding my kitchen waste on top.
A couple of months ago I needed to empty the bin to put in my bean trench and after I had emptied it halfway I noticed the worms were all in a layer/clusters above where I assume the dead rats went. I am now in a panic about the whole thing.
Question
Is that why the bin was leaking black liquid because I assume the worms wouldn't go into the dead rat zone? The compost had started to rot down above, but was rotted but different on the rat zone.
What on earth should I do with the compost still left in there containing the remains of the poison I assume? Would the poison eventually break down if I dig a hole in our woods and bury it. I have put the bin back on it and have barricaded it in so my hens can't get any where near it.
What do you actually do with disposing of poisoned rats or mice for that matter?
And what the hell do I do now. I daren't tell my husband I'm sure hell be furious with me.

Very worried in Seguinaud LOL.
Regards Linda
 

ps. is that the Seguinaud outside Bordeaux.

I would not worry about it any poison will have long gone just dig a trench and put the compost in and back fill with soil keep about 40 cms of soil on top of it all the rats will have composted away and there will be no reason for a fox or any animal to try and dig up a few micro bones . worms in a compost bin are always living in a smallish layer  deep down there is a lack of food whilst to high up in the bin its to hot so they live in the comfort zone damp warm with plenty of food  no other reason

Yep, that's the place, beautiful. , 2 and a half hours is just outside, when you're driving a truck to Spain from GB. lol.