Comment by jacquesm | Hacker News Reader

Comment by jacquesm | Hacker News Reader

What a great video. Dragonflies are relatively uncommon where I live now but in Canada they were quite common and some of those were at the upper range of the size of the ones that are still alive today. Imagine those 70 cm wingspan pre-historical versions, that must have been a sight to watch.

They're as closely evolved to what is the biological equivalent to an attack helicopter as possible. Seeing them hunt will make you very happy that you're not born as a small insect. I've found more than one caught on the inside of a large barn that was open on one side, they'd keep on banging into the windows on the closed side because that was the most lit up part of the barn, for all their technical advantages and various optics they are not able to fly back out of a box that they fly themselves into even though it is perfectly open on one side. They will just keep on trying until they exhaust themselves, then you can pick them up carefully and release them again outside the enclosure, hopefully to catch a meal soon with the remaining bit of energy after a rest.

It’s interesting to think that there are no boxes in nature, especially boxes with lights or transparent windows. So while it seems initially weird dragonflies and other insects really struggle with lights, windows, and human attributes, I suppose it makes evolutionary sense. They used to only have two “north stars”, the Sun and the Moon, and no boxes.

I wonder if there is any evidence for noticeable adjustments in insect navigation.

a box is any closed container — a cave, a hole in a tree, a dense forest

Though the light I think would almost always lead the way out in these cases

The change to the proposition above then must be that there are no vertically oriented transparent objects that are also solid in nature.

Given those restrictions the only thing that I can come up with is frozen waterfalls.

> So while it seems initially weird dragonflies and other insects really struggle with lights

Some birds also get confused by glass, although they do seem better able to consider an alternative (e.g. an open door) when one presents itself. My dataset is the small number that sometimes get into my shed when the door is open.

Tangential glass/bird related story time. I occasionally see small birds pecking at their reflection in glass. I once saw a Long-Tailed Tit pecking at my shed window and watched it for a few seconds. And then it went one way, and the reflection went the other! That's when I realised that there was a bird on the inside as well. Cue rescue mission (opening the shed door).

We are having a boom here, there are thousands of them. They are keeping the mosquitos away.

My lasting impression of them is from a forest walk a decade ago, where I was surrounded by hundreds of them, and I found them super clumsy. Every step I took I spooked a couple, and they would fly as fast as possible in a fixed direction, which resulted in dozens of them slamming into trees and knocking themselves out with an audible thwack.

Same here in Central Victoria, Queensland.

There must have been thousands of then flying around on the 29th January.

Meant to say December.

They are curious too, or territorial.

While bicycling through the forest in my youth, there was a small lake beneath a swampy area next to a small farm with cows and horses. Also many fawns/deer not far away.

They really thrived there, bodies large as a fat cigar. Every time I sped by that lake, they escorted me for a while. Going about 40 to 50 kph. Effortless. Like on rails, but almost instantly 'hopping' from one rail to another. Up, down, more near to my head, back away. For maybe 500 meters. Then turning back almost on the spot. Their checkerboard patterns glittering.

Very strange magic :-)

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