Opossums squeal when mating or fighting and produce thumping or scurrying noises when traveling through attics and homes. Opossums also have strong, sturdy teeth; they devour food rapidly, and a quick chomping sound might very well signal the presence of an opossum. These creatures vary in size and weight, and the noises they make while walking or running vary accordingly.
Opossums can be fairly weighty when fully grown, with the average weight of a brushtail possum being approximately 11 pounds. There is little variation in size between genders. The smallest species may grow to be the size of small rodents, such as rats and mice, and make similar sounds when running through attics overhead. Small opossums make a rustling or scurrying sound when moving about because their legs are shorter and smaller and create faster turnover. Larger opossums are much heavier on their feet and move at slower speeds. Like rats and rodents, opossums have large front teeth and can produce a great deal of noise when chewing on or breaking hard substances. Sometimes opossums emit high-pitched squeals. These sounds indicate tension and stress and are used in fights. Male opossums may make loud, throaty calls to warn other males away from their territories or food source.