Kirs are mostly covered in fur, due to being no bigger than a Cabbage White butterfly and being endothermic. They are skilled gliders for their size, to save valuable energy. Their wings are connected up, and their digits have turned into four mitten-like but highly muscular pads. Their antennae are also used to get the most out of their energy, due to being aerofoils. Kirs have large lungs and hearts, although their energy-rich diet means that their digestive systems have atrophied by a fair amount.
Kirs have highly modified heads. Their necks are very short. Despite this, they can still look around easily. The bone that joins the scrafs, cranium and jaws has evolved into a movable stalk for the jaw, which is also highly modified. The jaws have evolved into a tube, with the lips having turned into a highly mobile, sharp and bristly feeding appendage. This long mouth is used like a proboscis. This proboscis can spit rock-dissolving acid, that can also be used as a sting.
Kirs fly by flapping in short bursts, then gliding until more height is needed. They make hives on the ground out of dirt, rock, and minerals. These minerals are most easily found in bones, and most scavengers will happily let kirs break down the bones so they are more easily eaten. If the hive is disturbed, the kirs inside will begin squeaking loudly. If the hive is actually broken, the full wrath of every kir close enough to hear the swarm's devilish scream will be unleashed. They will stab their enemy with their proboscis and inject acids into the bloodstream. This is extremely painful, and most creatures will run away as fast as possible. (Alhtupuths can use their chemical reactions to drench the swarm, which almost always causes the kirs to flee.) If enough is injected, an animal will probably die from internal bleeding as their blood vessels dissolve.
Kirs keep their tiny eggs and hatchlings safe under the wall that their hives give. It usually takes a day for a hatchling to start moving around, and in a week they will be flying. After three weeks, they will be large enough to open flowers by themselves. The hives have underground reserves of regurgitated pollen-nectar sludge, which the hatchlings feed on until then. Older kirs will drink from the store, too, if they fail to get enough. Kirs can recognise individuals, though, so an older kir that is 'slacking' and drinking from the store too much is often denied access. If it continues, the kir may be attacked, killed and eaten by the others. Sometimes, the digested remains of a slacker will be added to the pool in an unintentional but ironic event.