This circa 2009 photo provided by Bent Christensen shows a perch fish 

This circa 2009 photo provided by Bent Christensen shows a perch fish in Sweden. Swedish researchers who did the study on traces of anti-anxiety drugs in water, suspect the little drugged fish could become easier targets for bigger fish because they are more likely to venture alone into unfamiliar places. (AP Photo/Bent Christensen)
Associated Press
This circa 2009 photo provided by Bent Christensen shows a perch fish in Sweden. Swedish researchers who did the study on traces of anti-anxiety drugs in water, suspect the little drugged fish could become easier targets for bigger fish because they are more likely to venture alone into unfamiliar places. (AP Photo/Bent Christensen)
View Comments