Behavioral responses of mice to the odor of cat urine and horse urine

The detection of predators by prey species is crucial in order to escape the threat posed by a predator. In mammals, the olfactory sensory system is commonly used to detect odors emitted by predators, and to determine how threatening the situation actually is. However, knowledge about this ability is still sparse and in some cases conflicting. The aim of the present study was therefore to assess whether CD-1 mice (Mus musculus) show behaviors such as avoidance, anxiety and/or decreased activity when exposed to any of the three odorants: cat bladder urine, horse voided urine or a fruity odor (N-pentyl acetate), with a blank solvent as an alternative in a two-compartment test arena. I found no significant differences between avoidance (the time that the mice spent in the different compartments), anxiety (the numbers of fecal pellets dropped by the mice), or the overall activity (the number of switches between the two compartments), when the mice were exposed to the three different odors. The fact that the cat urine derived from the bladder of the cat may explain the lack of avoidance responses, since bladder urine might not contain the same chemical components as voided urine. Bladder urine might therefore also lack the chemical components that signal “predator” to the mice. In conclusion, mice do not respond differently to the odor of cat bladder urine than to horse voided urine or to the fruity odor of N-pentyl acetate