A few years ago I forgot I had planted spinach in my garden and uprooted most of the plants, wrongly thinking them weeds. Then I remembered! Crestfallen at my memory lapse, I realized the plants were now too few to be worth harvesting. So I decided to let them go to seed, an outcome i had previously avoided, because I had heard that seeding would make the spinach leaves bitter. This time, however, that wouldn't matter.
A few weeks later, the remaining spinach plants bloomed, producing tiny whitish or yellow-white flowers. Once, when viewing them, I detected hints of movement. I looked closer, and closer. Getting on hands and knees, I lowered my eyes down to flower level.
The spinach flowers were being pollinated by a long line of the tiniest ants I had ever seen. If there had not been a line of them, I doubt that I would have perceived them. They were light brown, or dark tan, less than 0.5mm in length, and somewhat numerous. They were marching up the stalk and methodically wending their way into, and back out of, every single flower.