The effect of urine on the investigatory behaviour of male albino mice

The investigatory behaviour of male albino mice was studied in a test tank containing a sheet of unprinted newspaper as substrate. The first test category consisted of clean paper, whilst in all others one half of the paper was spotted with the following liquids respectively: (1) water, (2) normal male urine, (3) castrate male urine, (4) urine of testosterone-injected castrate males, and (5) urine of oil-injected castrate males. Preference for either half was measured by the accumulated time spent in each half and an approximate measure of activity was obtained by the number of entries into both halves. The results indicate the presence of a pheromonal factor in normal male urine which discourages prolonged investigation of an area marked with such urine. Castration eliminates the above effect, whereas treatment with testosterone propionate re-establishes it thus indicating that the urinary factor is androgen-dependent. The relevance of these results to the concepts of territoriality is discussed.