It's not really your business...

[Imogene]

Had a guy come in last night, and immediately ask, "You guys open?"
M: "Until 1."
H: "Why are all your doors closed then?"
M: "... 'All' of them?" If they were All closed, you wouldn't be standing in the store right now, would you?
H: "The one on the far side didn't open, and the one on the other side of this entrance didn't open..."
M: "We close that far door at or around 9 PM, to start congregating workers on this side of the store so we can keep a closer eye on late night customers, and I just locked the other door so everyone coming in or going out has to walk right past me." Not that it's your business, really...

[Summerfly413]

Our walmart has two entrances, and so does a super market across the street from where I work. If you don't go to stores late and try to go in a door that's closed it can be confusing, but you just go to one that's open. I tend to look and see what side of the parking lot most of the cars park on to determine which door is open.

[ShadowTiger]

My store only has an entrance and an exit door, so the only herding to be done is out. Customers can leave, but they cannot enter after closing.

[Tama]

My Walmart has two entrances too....if you call a taxi and say to pick you up at Walmart their first question is -- Which side?

Around 10 we close the side that is NOT in front of grocery (It's call GM I believe) to deter shoplifters. We close the back bathrooms at the same time for the same reason.