Higgins was able to convey a broad range of emotions through his facial expressions. Inn, who trained thousands of animals of many species during his lifetime, told reporters that Higgins was the smartest dog he had ever worked with and noted that during his prime years in television, he learned one new trick or routine per week and retained these routines from year to year, making it possible for him to take on increasingly varied and complex roles. Higgins's tricks included yawning and sneezing on cue.