I always wanted to visit Balkan region, but I'm affraid of scorpions. As far as I searched there's plenty of those terrifying creatures, but none of species I found was poisonous. So I have two questions:
If you ask the net, you'll find some Serbian Scorpions. But I hope you'll never find one of these in your tent.
I was a few times in Serbia, Bosnia and Croatia and have never a Scorpion in my tent. Also I don't know any scorpions from there being harmful/poisonous. Just be care full when entering your tent and keep the tent closed. If you want, you can put some lavender at the entrance and in your boots. My Serbian friend's mum put lavender below every window and every door at their datcha during the summer.
Besides: The sting of a balkan scorpion wont be worse than a wasp sting.
As a youngster I roamed a lot of times in nature in the former Yugoslavia, and I have seen a scorpion only once when I turned a heavy stone. It looks to me that scorpions there appreciate places where it's pretty cold in the warm South European summer. I've never heard any local people complaining about scorpions.
