There are a few people posting on this forum who may be able to help with this. I'm a daily visitor to a forested lowland heath just East of York well known to herpetologists. It seems to have been a good year for adders this year as I've seen far more than over the last decade (this could be because of more effective habitat management). I've never had a problem with them and even my six year old son stays calm and moves quietly away when we stumble across them. However I don't like the idea of waking up face to face with one, or worse finding one inside my bivvy bag. After spending a pleasant afternoon disguising an ugly bit of visqueen left lying around by untidy campers with the intention of bivvying under it this evening I was frustrated to find my discrete shelter had been occupied before I could even move in myself. Hissing snakes put me right off snuggling down on the floor for some reason. Am I being unnecessarily squeamish? This adder showed no sign of clearing off. Has anybody any experience of adders as bedside companions? Is my gut instinct to avoid sleeping on the floor in a high adder zone rational common sense or would they find some place else if I'd sat it out for the evening?