Recently, we were on a site, and we came across some reptile and amphibian fencing. Normally made of sheet plastic, this type of fence is designed to keep reptiles and amphibians in – or out – of an area. It works well, provided it’s installed correctly and maintained well so any damage is repaired quickly.

Why would you want to fence reptiles and amphibians in, or indeed out?
Well, if you’re developing an area, you might want to trap them and translocate (move!) them to a safe area away from the development. Conversely, you might need to keep them away from a development area during the works. It’s just a way of keeping wildlife safe.
Cool! So what does it look like?
It’s about knee height, plastic sheeting, attached to wooden stakes driven into the ground. You’ve probably seen it along motorways - it’s often green, but it can be black. The colour isn’t actually that important!

Ok, so what about the stuff you saw?
The fencing we saw was made of geotextile, which is a woven material. It’s this stuff (this was on a different site):

Hmm, that looks ok to me?
You’d think, right? Except the fence we saw had a common lizard on it. Sunbathing. Right there on the top of the fence. The fence it had climbed. Yes, the fence that was meant to be keeping it in the safe area, and away from development. Whoops.
The woven nature of the material meant that common lizards could climb it pretty easily. It’d probably work fine for slow worms, which are lizards without legs, and for snakes. But it definitely wasn’t doing the job for common lizards, and I wouldn’t like to test it against amphibians either.
Sometimes, the devil is in the details.