The picture is quite small. Could there be a sticky area around the sweet, which is trapping material blown by the wind?

Why did these ants arrange the plant debris in a circle around this sweet?

Did You see the ants arranging the debris?

Why do You ask a different question in the following

text?

This is style typical of papers like Sun or BILD.

Disgusting

If the ants were clearing an area around the sweet their behaviour may depend upon species. I do know the way in which some ant species clear an area around the entrance to their nest. The idea is to pick up a bit of debris and walk away with it. When another bit of debris is encountered the ant puts down the bit it is carrying turns (I think a right angles) and goes off in search of another bit and keeps on doing the same thing. Many years ago I saw a computer simulation of this and it cleared a circular area of ever increasing size. It may not be very efficient but it is the simplest algorithm that can be used to clear an area of randomly placed debris.

I am sorry that I cannot remember anymore details. The work was done to investigate how very simple machines could be designed and used to do this sort of job.

stewart, I have also noticed that when an ant hole is on sloping ground. the distribution, mass, distance and direction wise is asymetical and I'll bet that energy -wise, this is optimal and may be "emergent" from a simple algorithmic behavior.

Many of the ants in a colony are engaged in collecting nest material, such as leaf litter for bedding. On their way back home they came too near the tempting sweet, dropped their cargo, gorged themselves and carried that back to the nest, completely forgetting their original engagement.

Because they came from all directions, the material was dropped in a neat circle aroung the sweet.

Joop van Montfoort

7 Penny Hill

Croyde

Devon EX33 1QR

joopvanmontfoort@gmail.com