I live alone in a terraced house. Back yard rather than garden, with a back lane.
Someone just knocked, twice, at my back door. Dark in the back lane. It's a minute walk round to the front, where I MIGHT have answered (might not now it's dark tho). Creepy as fuck.
Would you have answered the door? I found it very odd that someone would go to the back door (even in daytime). There's no reason to. My car isn't there. My bins aren't out. I have nothing in the lane itself.
I ignored it. After they'd gone I checked the doors were locked (they were).