 The heating and ventilation systems in a poultry house must be continuously monitored to keep the moisture content of the litter controlled so that the litter remains friable (easily broken up or crumbly).If the litter becomes too wet and the litter is allowed to become “sealed”, then the birds will be living on a damp, slippery and sticky surface.This sealed litter is what is referred to as being “caked.” In this condition, the litter is simply saturated with water and is unable to dry out.