Ants

Why are there so many ants on my cherry tree? I googled and look what I found:

The tendency of the ants to settle on plants is actualised by means of a fluid called "nectar residue" secreted by the plant. Nectar residue liquid plays almost the role of an unresistable invitation for the ants. The plants secrete these fluids at certain periods. For instance, black cherry trees secrete this fluid actively three weeks during whole year. This timing is by no means a coincidence, since this three weeks is the only period in which a kind of caterpillar called "eastern tent caterpillar" harms the black cherry trees. Thus, the plant has only one way to be saved from the harm: retaining the ants live on itself in order to have them clean their leaves from the caterpillars. Secreting a fluid, the plant makes the ants do this which it is itself unqualified to do.

That is so cool.

Our cherry tree also had eastern tent caterpillars right now. In fact, there are about 3 different kinds of caterpillars eating most of the trees in my yard. I was annoyed with the ants, thinking that they too were some kind of pest. I had no idea they could be helping control the caterpillars. I'm so in awe right now. :-)