I need some help with my A2 biology coursework please. Its about woodlice and their problem of drying out?!?

Ok right well i had to investigate if, the reason why woodlice may decide to rest in places such as under bricks, where it is damp, is because of their problem of drying out. I used a choice chamer and made up 4 different humidity's using different mixes of water and glycerol.0% humidity was 25cm3 glycerol and 100% humidity was 25cm3 water and i also did 30% and 60%, and i placed muslin over the top and held it in place with the lid of the chamber, then put 5 lots of 10 woodlice in the middle and left it for 10 mins and then counted how many were in each chamber.....i did 3 repeats of these 50 because i needed averages, and at least 50 to do a statistical test. The results turned out to suggest significance, in the woodlice majority being on the 100% humidity section, least in 0% and increasing inbetween, but i dont understand exactly why they did this, i know its something to do with simple behaviour and homeostatic control :s but i dont quite understand?? Help would be appreciated.