So every night about this time, I open the front door, the dog goes out to pee, and we go to bed.
Tonight I opened the door and a BAT flew into my house!! 
I didn’t know what else to do so I turned off all the inside lights, left the porch lights on and waited for it to leave 
That’s kind of calm of you. I can picture extended screaming, desperate calling of various organizations, etc., if that happened by us.
I wasn’t afraid of it. But I didn’t want to get too close. My neighbors had a bat in their house about a month ago and when they discovered it, they couldn’t know for sure how long it had been there which meant that there was a very small but non-zero chance one of them could have been bitten (apparently, they can bite you in your sleep, and you might not even know it) And so the whole family had to do a full course of rabies shots. 
Um, don’t bats like the dark?
Turn on all the indoor lights and turn OFF the porch light.
That’ll do it.
Disclaimer: I’m no Chiropterologist, but I can look up that word using Google.
Oh, and it needs to be added to the “correct word” list here.
Yeah I thought about that while I was standing outside. But if I had done that I wouldn’t have been able to see him fly out unless I was inside with him.
I figured the porch lights were what attracted him somehow in the first place. And it worked so
Funny, I’ve had the same nighttime routine with my dog for two years. I just let her out and as long as it’s not buggy I just leave the door open.
Not anymore!!!