Sluggish wasps at the rear of my house

Over the past few days I've found a few extremely sluggish wasps at the rear of my house - it's south facing so gets a lot of sun and the wasps are usually found on the inside of rear window or on the sill or just outside the rear door very slowly crawling along the ground.

I can find no sign of any activity inside or outside - none flying around in or near the house and no sounds of buzzing whatsoever. It's a bit of a mystery where they are coming from.

The fact that they are sluggish is puzzling too, it's not as if the fruit is yet ripe.

Any ideas please?

 

Any orchards near you?
Could be they have been sprayed.

 

No orchards, but in the rear garden at the south end we have about half a dozen assorted apple trees, although they're not close to the house (about a 30 second walk away - it's a long garden!).

There is a lot of Maize growing in the field next to the house but it's not been sprayed (I'd have noticed). Also the Maize was there last year with no wasp problems.

 

Puzzle solved .......... there's a wasp nest the size of a football in my attic.

I went up there to have a look around, switched on the light, a wasp mugged me and stung me on the neck and after I backed off I saw the nest. A pest exterminator is on the way to sort it out. I'd do it myself (I've disposed of one before in an outbuilding a few years ago) but in the confined space of the attic with nowhere to run I'd rather not risk it without suitable wasp-proof clothing.

Edit: now exterminated