Four people sit on the seat meant for three in a Mumbai local. When there are three people sitting on the seat, a fourth one will come. He will not say anything; just tap the shoulder of the person sitting in the corner and gesture with his hand to move a little. This will create enough space for one cheek of the fourth person. If lucky to find thin people, the fourth guy can also sit comfortably. This is called "adjustment". The bees also seem to have made the same adjustment here.