Teamwork 2

I took this picture in Corse, while camping at Plage d'Arone. I found these three ants busy in carrying a grape to the nest. They simultaneously attacked the fruit and began to cooperate, by placing at a distance of 120° from each other.

Once again, the question is whether we're in front of intelligent behaviour or not. Appearently,  this doesn't seem to be the smartest way to achieve the goal: every ant pulls in its direction and, even if they want to reach the same place, their vectors of forces are often opposed resulting in no movement at all.

So, are they "stupid"? Do they just grab the good, pulling toward the colony as a consequence of the pheromone stimuli, without any agreement? Maybe, yet I don't think it is so easy. They usually look forward when bringing stuff, therefore pulling obstinately in one direction can result in the unpleasant side effect of blocking into obstacles. By applying more forces, the group follows alternative paths along the way, avoiding the traps.

For the record, they took about an hour to carry the grape to the colony, distant less than three meters.