The ants are one of the 30 or so species of the genus Camponotus that occur in Israel, possibly C. alii. The flower buds of capers (and many other plants) have tiny nectar glands on the outside that attract ants. The ants themselves do no damage, and indeed, the ants' presence deters flies, weevils and such from landing on the buds and laying eggs. These insects' larvae could do real damage to the reproductive structures.
Beautiful, clear pictures, by the way.
Regards, James C. Trager of the AskAnt Team