Behavioral indexes of poor welfare in laboratory rats.

A study compared the behavior of rats kept under standard conditions with the behavior of those from enriched, semi-enriched, and single-housed conditions to determine whether standard conditions have detrimental effects on nonhuman animal welfare. The subjects were 35 female Hooded Norway rats. Using an emergence box, open field, and Hebb-Williams maze, the study measured the subjects' behaviors. Housing conditions significantly affected the behavior of the rats as measured by all 3 procedures. The results of the rats from standard conditions were intermediate between those of the single-housed and the more enriched groups. Thus, enriching the standard environment would ameliorate behavioral deficits in rats kept under standard conditions.