sleeping off the ground

Hi Guys,

Have been told a long time ago, and seen on many sites that there is a need, when camping up north, to sleep off ground level, but haven't been able to find out why and if this is an absolute must. Can any of you well travelled folk guide me as to why and any recommedations as to how? Mik & I are heading to cape york in a couple of months and whenever we've been camping previously have only ever thrown the foam matress on the floor of the tent and still managed to get a good nights sleep, but victoria isn't known to have this need.

Any advice greatly appreciated
Thanks
Mik's better half (Di)