|Culex, probably the Northern House Mosquito, male.|
... and I let him be; he's a guy; he won't bite.
The female is the nuisance, and sometimes deadly. Her mate wanders around drinking plant nectar and caressing aphids; he's not interested in us. In the day, he sleeps. At night, he listens.
Those big, feathery antennae are his ears, so sensitive they can pick out a female of his own species as she flies by, on the hunt. Each species has its own buzz frequency, up to 500 beats a second, and the males buzz at a different rate than their mates.
These "ears" are among the most sensitive known in the animal kingdom. (E-Fauna, Culex pipiens)
The song changes when a couple meet and hit it off; they modulate the wing speed to match each other's, taking themselves off the "available" list.
They mate, and the female gets hungry. She needs blood for her eggs to develop properly, so she goes hunting, whining in your ear when you're trying to sleep, sneaking up on you at dusk and raising welts on your ankles and the back of your neck, ignoring your somehow immune companion and dive-bombing you.
Or worse: driving in the Chilcotin in the summertime, we drench ourselves in repellent any time we want to stop and stretch our legs. Otherwise, within seconds a horde of ravenous mosquitoes, thousands of them, a swirling black cloud of them, descends to feed. There's no batting them off; a fresh batch is already settling on the swinging hand.
"What do they eat when they can't get human?" we've asked.
Birds, mainly. But they'll take dogs or other small mammals. And while they're waiting, they'll fill up on plant juices, like their mates.
Do birds itch, I wonder?