Sentence:  Poorly ventilated <WSD>coops</WSD> are likely to result in losses by suffocation, particularly during hot weather, when the <WSD>coops</WSD> are overcrowded. The bottom of the <WSD>coop</WSD> should be built solid of one-half-inch boards to prevent the birds' toes from sticking through and being injured. 
Meaning of the word marked with <WSD> tags:  A basket, pen or enclosure for birds or small animals.