how do you respond to this?

Ethically we have to consider the needs of participants whether they are animal or human. Even in animal studies we have to consider human needs too since there has to be safety protocols to ensure human handlers are not hurt. Some studies involve both human and animals. For example, there is a big interest in further understanding the role of support animals and animal companions/animals as companions. While the animal may or may not be an actual participant in those studies, they require thorough plans for the care and well-being of both humans and animals. That can make a study very complicated. I like that you mentioned legal here too. We focus a lot on ethical but sometimes there are also specific laws we need to understand and those can be federal, state, and even loca