The preference test is one of the only behavioural test, which gives the animal an opportunity to make a free choice or indicate what it prefers and, therefore, it is widely used to evaluate whether an animal prefers one set-up to another. Providingwhat the experimental animal prefers (eg grids) will reduce stress, good for both experimental reliability and animal welfare.In the present study the rat’s preference for different cages was registered and recorded by digital weights This study showed that this relatively simple set-up was applicable for registration of the preferences for different housing conditions, such as bedding or grid