Most likely the same things that motivate people to take their dogs, cats, ferrets and such: Education and a love of the animals.

I know that if I had the time, I would SO take my big female normal out. Heck, I want to make a career of taking my animals out to places to educate people! There are too many folks out there whose ignorance is simply from lack of education. When you tell them the truth, their eyes light up. Naturally there are those whose ignorance comes from stubborn, superstitious, old-fashioned beliefs which are so wrong. Those people...you can't do a thing about.

But, most people just don't know and really appreciate the education. I run into people all the time who don't know a single true thing about snakes, and thank me for clearing things up. In fact, some of them continue to ask me questions...like a certain bus driver from India who thought all snakes were poisonous and, since I corrected him, has been asking me more questions every time I'm on his bus.