awesome!!!
Well, no other evidence of any kind of animal (well, other than me and some bugs) has been found. I’ve been looking. I have found no other droppings, no holes, and the slider and windows have been closed due to the cold weather we’ve been having around here.
Right now, the only way anything could be getting in here is via my door that’s inside. There is a gap in the jam, but I have a rug over it to keep out neighbor smells, etc. The rug would move out of place if something was trying to squeeze it’s way in or out via that method.
I’m completely baffled.
It’s a mystery for the ages! LOL
I am amused by the responses – keep 'em coming if you got 'em!
You’ve ruled out falcon, right? Being that you’d be able to find it if it were in your house…
Sorry about the slow response to my summons – I just flew in from Washington DC (and boy, are my arms tired).
It looks to me like the feces of a rodent. Odds are pretty good you’d notice bats in the house, so I’d go for mouse, vole, chipmunk, ground squirrel, or something of that ilk.
Is there anything in the rodent family that poops one turd then never seems to come back? I’ve been looking and have not yet found any further evidence…
Also, if I didn’t note it before, this poop was found out in the open about six inches away from the side edge of my bed…
Oh! and rimshot for the joke 
You suspect he is lying to about this?
Well, he could say he still has the dropping, but, in actuality, threw it out because they’re probably not going to do anything about it…
I vote bat. They can wiggle through a half inch gap. He may have come in, done his business, and left, which would explain why you haven’t seen him.
Or he could be snuggled up behind your drapes, or under your bed. I’ll bet he’s clinging to the underside of your mattress right now, waiting for darkness . . .
More likely he’s reading this over your shoulder RIGHT NOW.
.
I don’t have drapes or curtains (all blinds), and have a Select Comfort bed which has no box spring and, therefore, nothing for the bat to hang on to (besides, I already checked under my bed to see if there was any further evidence of habitation by rodents, etc.)
I still vote bat.
I think you’d have heard a rat or other rodent, and they need a bigger opening than a bat does. We had four bats in our house (not all at the same time, thank god), and we didn’t know any of them were around until we saw them flying around the ceiling fan. They didn’t stop coming in until we plugged a small gap on the front porch, between the wall and the floor.
Do you have a ceiling fan? Look at the top of the blades. Space between the kitchen cabinets and the ceiling? Look up there. Do you have a clothes dryer? Check the vent opening. Check under the sink too. Don’t just look – get out your broom or your feather duster and swish around.
I know it’s there. 
Nope, no ceiling fans and I’ve been in and out of my kitchen cabinets. Remember, it’s been too cold to have the windows open and there are no gaps in my windows or slider. It’s a very small apartment so I have bedroom window and slider in living room.
Plus, the three bats that hand around here are accounted for. I see them every night outside doing their aerial acrobatics.
I have had many pet rats (14) and I don’t think that looks like rat poo!
That’s good news! 
It’s a bat. The bat lives in your closet and the thump sound you heard on two different occasions was it hitting the window trying to get out of your house. It came into the house when you opened the window one day. You don’t remember opening the window.
Best explanation I can come up with. Rats don’t go “BANG!” but bats sure do.
ETA: the reason you can’t find the bat is because it’s dead in an area you rarely look at. Under the bed, or in your curtains, or in a sweater in your closet.
Maybe whatever made it was never inside your house to begin with. Is it possible that you brought it in from outside somewhere, stuck to your shoe?
That’s exactly what I was thinking back in post #2. (Reasserting my claim to the prize in case I was right. Also, “Post #2” pun was intentional, couldn’t stop myself.) Although now I’m doubting my own logic (and yours)-- wouldn’t echolocation prevent a bat from flying into a solid surface in the dark?
Agreed. Although… wouldn’t it be smelling by now? Even a TINY dead mouse will stink up a small room.
Regardless, I still think you’ve laid out the most likely scenario.
.
I suppose I should have updated the thread with the fact that I think I found out what the noise was that I heard. My freezer doesn’t exactly work right and I heard that same noise the other night, but it was actually from my kitchen. It reminded me of the last time the freezer was acting up and it made loud bangs just like what I heard. So, I’m thinking that solves that part of the mystery.
I never have the screens open when the bats are flying, so I really doubt it’s a bat. I would think that by now there would be some stench of a dead animal and there hasn’t been anything like that.
I don’t wear my shoes around in the house and I certainly hadn’t worn my shoes in the days leading up to finding that little present on my floor, so I doubt it came in on my shoes.
Considering the number of beetles and other assorted bugs that get in here, could it be possible one of them dragged it in?