The phrase "obese mice" refers to a group or population of laboratory mice that have an excessive amount of body fat. Obesity in animals is typically defined as having more than 25% body fat, and obese mice would therefore be those with even higher levels of adipose tissue than this threshold. This condition can result from a variety of factors such as genetics, diet, or hormonal imbalances. Obesity in animals is often studied to better understand the underlying causes and potential treatments for human obesity.