My first reaction was - isn't that a bit early for peas? But then I noticed that you are down south, and it's "indoors" peas we are talking about...
Considering your ongoing problem, I am just visualising a kind of tunnel around the greenhouse (or around your property), entirely enclosing it, "manned" with about half a dozen hungry cats... But I also know the soaking-in-paraffin trick. Don't know what it does to the soil, though. I generally start peas, beans etc off in the house (if I find a spare corner); the season is just a bit short up here. And I tend to forget to start them off early enough anyway, so it's generally hit and miss.
I spent a summer in France once, on a goat farm, and caught ten mice in my room with just the one hazelnut! Hazelnuts seemed to work best; they stick to the trap, even when the mouse tugs at it. Very economic.