It wasn't really an issue, They'd go in between sunset and one of the twilight light levels, and that was that. When we did it without the automatic door, there

It wasn't really an issue, They'd go in between sunset and one of the twilight light levels, and that was that. When we did it without the automatic door, there was a lot more chasing type manual labor just getting them in if it was early, or we'd forget and it would be super late. Didn't ever lose one at night, but there were definitely daytime predators that were an issue. (mainly raptors)