To begin with, Waddell cautiously chose the word "motivation", rather than "hunger", to describe the flies" state of mind – he suggested that they were more motivated to find food if it had been withheld. "And people found it a little problematic," says Waddell. Some other scientists felt that this was too anthropomorphic and preferred the term "internal states". "So I often had arguments that I thought were essentially meaningless, because they were just playing with that word," he says.