Did Underwriters Laboratories test for this?
I have not yet actually seen the special UL "bp" (bat-proof) endorsement on any coffee makers. (I just made that up.)
But I am sure some consumer group is going to demand it sooner or later. "Did you know that people, mostly women, children, and minorities, are dying everyday due to bats in coffee makers? We demand that something be done to prevent this senseless loss of lives. Even more important are the poor bats that are dying a senseless and excruciating death in 5000 degree water!"