Compost: Grass snakes

My favoured recipe for compost (mixing lawn mowings in with the poultry run straw which results in very rapid and hot breakdown) has attracted an unusual number of grass snakes this year. The current heap has at least four regulars, one a good four to five feet long. They have been breeding in next doors lawn clippings heap for years, but this is the first year I've ever noticed more than the odd juvenile in my heaps, or what was formerly the slow worm reserve (a metre of old pond liner under a medlar tree).

Below is a tiny one; the next one is a huge adult, over an inch in diameter, difficult to tell differences in scale from photographs. Hopefully they'll control any rats that are breeding in the heaps too, though I suspect the amphibians are an easier meal.