Do housebats in Nebraska migrate in the fall or winter? How do I get rid of them?

The following site provides various methods such as sealing the entries once the bats have left to feed at night. There is plenty of info there on the subject. Once there, scroll down a bit to find the rest of the info about getting rid of them.

Excerpt:

The traditional way to exclude bats from an occupied roost involves five basic steps: (1) identify and close all indoor openings through which bats might gain access to human living quarters; (2) close most confirmed and all unused potential exterior exits, leaving only a few major openings (it's best to complete this within 1 to 2 days); (3) at night shortly after the bats have departed to feed, temporarily close the few remaining, major exits;

http://icwdm.org/handbook/mammals/bats.asp