i've only had trouble with moles maybe once or twice, they just left a huge trail in my yard of ground up dirt. they didn't give me much trouble, i wouldn't worry about them too much unless you are having serious issues on a weekly basis.
I'm sure that using a large industrial fan like that or even just a few regular fans would help solve your problem of "very little air circulation" and help push the air around...now just make sure it has somewhere to go...open all the windows and even leave the door at the top of the steps open...