to ask my neighbour why in the hell they are constantly drying black bin bags

[KeiraKnightleyActsWithHerTeeth]

My next door neighbours constantly have black bin bags on their washing line. Not in their main garden but in the side return, right next to our house. Our kitchens look into the other but we have a fence up which just about blocks us from seeing each other. However day and night for the past 2-3 months they have had black bin bags on their washing line. I wouldn't give a crap about what people have on their washing line ordinarily but it makes a right din, especially in the wind we have had recently. DS13's bedroom is at that end of the house and says he can hear them rustling really loudly all night long (which I know sounds ridiculous but they must have 4-5 bin bags rustling away at any one time).
These bin bags keep blowing up in the air too and our dogs are losing the plot about it, they don't usually bark much but 15ft glossy black apparitions springing up is sending them mad.

Every morning, when I'm in the office (we have an office annex in the garden so can see directly up their garden without effort) I can see her taking bags off the line and replacing them with new bags.

Come on, what am I missing here? Have a missed a bizarre trend? They are bizarre people as it is but I can't figure out wtf is going on here.

No suggestions but I really want to know now

Maybe they are frugal weed growers

Placemarking ready for the obvious upcoming alarming news story and court case of the binbag killers.

I need to know what they're for.

If it were me, I'd definitely ask because I'd need to know and I'd need them to know how annoying it is.

Maybe they were trying to find out if you'd been slagging them off on AIBU so are now searching "bin bags on washing line" to get your un and find out.

Or it's art

Place marking...

You could just ask . get the kids to ask

What you need to do OP is go out in the garden when they are taking their bags in and say "do you find they dry well on the line? I dry mine indoors but might try them outside" they'll obviously think this is perfectly normal conversation and respond with how well they dry and add on something about how that's beneficial to the purpose they are used for. And voila! You have your answer

Of course they will have their bin liners on the line. Surely everybody knows bin liners can't be tumble dried?

Oh shit... dives back it garage to take bin bags out the tumbledryer

'Hi Neighbour, I need to know, why are there binbags on your washing line? I'm not being nosey but MN has told me to find out'

Tut tut, Jack.

They are preppers, getting ready for the zombie apocalypse. They are shitting in the bin bags, then at night they are burying their shit in your garden using a small orange trowel. A quick rinse and a bit of an airing on the whirlygig and the bags can be re-used.

But how would shitting in bin bags and burying it make you more prepared for the zombie apocalypse?

#thatsaquestioniveneveraskedbefore

Maybe they use the bags to line the indoor recycling bin and wash and re-use them? My council won't empty the recycling wheelie bin if there are black bin bags in there. They will take carrier bags, which are handy for the bathroom & bedroom bins but not big enough for the kitchen one.

And trying to coax my housemates into emptying the kitchen bins is a waste of hot air. I just think of the benefit to my arm muscles as I carry the overflowing bins outside and lift them into the wheelie.

love it Chardonnay and Jack

Very mundane, but I'm guessing someone in the house hates/has some kind of reaction to that very strong solventy plastic smell you get from some brands and they're airing out a few at a time between unrolling and using them.

Or they're setting out a landing path for goth alien visitors

Maybe they wet the bed and put them on the mattress then wash off the piss and reuse

OP please ask them
Or put some black bin liners on your washing line and see if you get inititated into something....

They are using them to collect dark to put on people's washing in the day time.

Back in the day, I used to know a couple of people who wore them to football training to make them sweat more and lose weight (it was a bloke thing!). Possibility?

Maybe they are their bedding but they've been darked on

I think you've cracked it, Glitter

Maybe they wet the bed and put them on the mattress then wash off the piss and reuse

I do not want to be around for that scary walk to the bathroom!

MyWhatICallNameChange "Maybe they're not bin bags but dementors and their house is really a prison for wizards?"

That's got to be the answer! It's obvious now. All the other ideas are just silly and far-fetched.

Oh I know what they're doing! They're collecting air for their jar of air company.

getting our shopping delivered...from Morrisons

OOOOOOOOooooooooooOOOOOOOOOO!