Snakes for killing tree-rats

Question
Hi,

I have a villa with a large garden on the Northern Italian coast, c. 150 metres wide and c. 100 m long with many trees in it. My family only use it in the summer, from May to September, every year. We are one of the few gardens which there which do not use pesticides or other artificial chemicals so we have lots of butterflies/dragonflies etc. etc. However, we also have a large tree-rat infestation. We used to have 2 bull-snakes to cotnrol the rats several decades ago, but the then gardener foolishly killed the snakes as he was unaware of their use in the garden. Anyway, what snakes would you recommend for controlling the tree-rat population? Obviously, any such snakes should be easily available from pet-stores in Nice, France, they hopefully(?) would not need a licence, they should be avid tree-climbers, be able to withstand the climate in Northern Italy, be independent and not need regular maintenance/feeding, and be harmless to small children. Ah yes, my mother wanted only 2 snakes, a male and a female, but I pointed out that this would lead to massive inbreeding over the generations, and if just one of the snakes died for whatever reason, then breeding  could not occur. How many snakes would you recommend to kickstart a stable snake population in our garden? Thanks! Gerald

Answer
As I am not familiar with the weather of Northern Italy, nor what snakes are legal in France I'm a little limited on my answer.  However, if bull snakes were doing the trick before I'd go right back to them. Inbreeding is not as big a problem with snakes as it is with mammals but 2 is a small number to start with if releasing to the wild.  We have to assume (unless you buy large snakes) that many will succumb to predation.  So, I'd buy maybe 2-3 males and 4-5 females if buying babies.  If you can get adults then it would probably be better idea to do so.

Any of the rat snakes we have here in North America would also perfectly fit the bill.  Problem is I'm not sure how cold it gets there so some species would be better than others.  Here in FL we have what we call a "yellow rat snake" Elaphe obsoleta quadrivitta that would be perfect assuming it could survive your winters.  I guess the only way to be sure would be for me (and my family... err team of scientists) to come over and spend a few weeks during the winter enjoying...  no wait, examining the garden and villa, to relax... no, determine, which snakes might be best!  LOL