For reference, we have 128 different species of snake in North America.
That’s a lot. Do you need that many? Maybe send some of them to other countries that are lacking in the snake department.
Although, like I was saying, the climate in northern Europe isn’t really good for reptiles, and the few there are are generally quite docile.
In Britain of course, being really a quite small island, most of the really wild animals were hunted to extinction a long time ago. Adders are venomous but a single bit is not likely to cause anything more than nausea to a human. The most dangerous things you’ll find in the wild here now is maybe the odd wild dog, or a badger could give you quite a nasty nip if you get too close.