Photographing bats?

I will be going to a known bat cave to photograph their evening spiral into the sky.

Obviously, this low light high shutter speed work. Can I get some tips, tricks, setting advice, etc. Please...

I'll be shooting my new D7200 and have these lenses to use: Tokina 11-20 2.8, Nikon 18-140 vr or Sigma 150-600C

Thank you!

I think the Tokina 11-20 will ensure you miss nothing and is easier to focus and a relatively fast lens too. You will need to consider your ISO very carefully between 6400 and 25,600 depending on shutter speed 1/1000-1/2000 sec so you may have to shoot f2.8-f5.6. Second choice is the 18-140mm VR but remember AF may not work under these light conditions, the 150-600mm would be very difficult and you might miss a great deal trying to compose and focus your shot.

Your logic makes sense but, the wide angle tends to make things look very small unless I can get very close....

You don't have to use the widest setting, I am not sure how far or close you will be to the bats and I am sure you won't get a chance to change a lens in mid shoot. If you feel safer by all means go for the 18-140 vr but you will need to pay close attention to the focus

It seems quite challenging because I should shoot a higher f stop in order to get more of the spiral in focus, shoot fast enough to freeze action and deal with low light... Wish I had a 70-200 2.8!

You should probably try and shoot @6-7fps maybe mirror up. I agree with no prior experience this will be pretty challenging, would love to see the results...