Bridal flight / Nuptial flight of the Yellow meadow ant, Heesch, Netherlands

(hard to see, but this photo features both the female workers (tiny, orange) and the winged males (large, black))

Today I was lucky to discover a "Bridal Flight" in the small lawn of our backyard.

This particular species lives entirely below ground, where they milk aphids that feed on the roots of grass and other plants for honeydew. This ant species takes this symbiotic relation quite far: they create large underground chambers where said aphids can feed in peace, uninterrupted. They even hatch the eggs of the aphids to secure a new generation of "cows" and then transport them to the feeding chambers.

These ants don't like direct sunlight, yet do need some of its heat for their nest. In a natural habitat with tall grass, their nest will look like a bump above ground. In a situation with short grass (mowed lawn), the entire nest is below ground, and you're unlikely to know it even exists...unless you're lucky to witness this event. I found two nests on the same lawn, both having their bridal flight.

Most of the colony consists of female workers, which are small (3-5mm) and orange. They have a very juvenile or albino appearance, yet are adults. Unusual for ant workers, they are not uniform in size. Small workers take care of the queen whilst big workers handle food logistics.

The female workers make the call on timing the bridal flight. The decision is based on conditions, for many species it concerns the first hot and moist day after a cooler period in summer. Amazingly, timing is so reliable that this event is synchronized. Every independent nest will fly on the same day. Across the country, or territory with similar conditions.

The decision involves the physical process of female workers enlarging the nest opening, otherwise the queen can't get out. Next, ants are chased out of the opening.

Which sets the bridal stage. It largely consists of male ants, which only exist for a few weeks of the year, and are large, winged, and black. They come out by the hundreds or thousands. They are crash pilots, as they've never before used their wings. But they must, in an effort to reach the queen.

The queen flies as high as possible, as it favors to mate with a male from another nest, and not one of her own brothers. Yet the brothers try, climbing, crashing, pushing competitors down, all to reach the price. The lucky male to succeed, will deliver enough seed for the queen to lay eggs for life.

And then all males die.

The queen may return to the nest for expansion, or create a new nest elsewhere. They'll try to find a safe place for the winter and start the colony the next spring. Some nests may be founded by multiple queens, yet only one egg-laying queen will remain, the others are killed by the workers.

Some people unaware of these nests freak out by this sudden unexpected explosion of ants, and may try to exterminate them. Don't! This is a critical day in their life cycle, let it happen uninterrupted. All males die and will be picked up by birds. Female workers retreat to the nest. The scene cleans itself up. Therefore, enjoy it. It's a marvel.