Stirge

Stirge? They are a plaguing menace is what they are! The little bastards nest anywhere that bats do, and their thirst for blood is a damn sight more predatory! Once they latch on to you, or your livestock, you aren't long for this world, laddie. Listen to your elders and stay out of that cave!

Ex-adventurer, Galeth Branch, to his son on his 14th birthday

Introduction
The Stirge ( Anophelli Chiropterus ) has been the subject of debate among naturalists for centuries.

Those who argue that the creature is the product of natural evolution point to it's distant cousins, the vampire bat ( Diphylla ecaudata ) and it's own bloodthirst, as well as the stirge's practice of sleeping inverted by the feet, in dark, close quarters. It's mosquito-like proboscis secretes the same numbing agent as the insect species when it feeds, so that victims are unaware of it's presence, if they themselves are asleep or unconscious.

Those who argue for a magical origin, the product of some wizard's meddling, point to it's difference from the bat. Stirge are not blind, instead navigating through infravision, sensing the heat of their victims from over 200 yards away. Stirge are also incredibly strong when latched on to a victim. The talons of their feet are pointed and seem made for piercing thick hide and armor. It takes a very strong man, or several men of average strength to remove a feeding stirge, and often the victim is injured during this process - either being struck by an errant weapon from a friend, or from the sheer trauma of having an 18-inch proboscis being ripped from the flesh.

Physiological Observations
Stirge, as mentioned, can see heat sources. They will flock to these sources in great numbers; the entire colony will attack one victim in most cases.

They do not appear to have a language, but some have theorized some form of chemical communication, as there is a slight acrid smell to the air when the creatures are feeding. (Others have argued that this smell is an oil secretion native to the species, and this is simply a natural skin emolient)

This is not to suggest stirge are blind in daylight. They appear to see perfectly no matter what the light level.

The stirge is a formidable creature. They flock in swarms in the hundreds, and some have reported seeing huge swarms of more than 1,000 of the tiny, flying beasts. They have a wing-span of slightly over two feet, and can fly as fast as a bat, but with more agility and control.

Once they have fed, they detach and fly towards the colony's home, and at this time they are not as manueverable. The weight of the bloodmeals makes them more slow and sluggish.

Social Observations
The stirge appear to have social structures much like bumblebees ( Bombus terrestris ), with a single female serving as Queen, an egg-layer. The eggs are laid en masse, usually 10-30 per month, for up to 9 months a year. In the winter, the Queen goes dormant and all the other stirge form a protective "bubble" with their bodies to keep the Queen warm. The eggs are laid in the stirge's own fecal matter - much like bats, their excretions form large piles beneath the nesting colony. The gestation time is 3 days and then baby stirge hatch. They are weak at birth and need large amounts of blood to evolve into the adult form. This generally takes another 3 days, at which time the stirge will become aggressive and hunt any creature in their territory regardless of size or disposition.

After 3 years, the Queen dies and one of the colony stirge has a hormonal burst and evolves into a Queen. The colony usually moves at this point and finds a new lair. This always occurs at night.

That is where the similarity with bees ends. There are no specialized roles outside of the Queen.

Colony numbers generally range from 30 to 300 creatures. Larger colonies have been observed, but once humanoids discover them, they are aggressively hunted down to more managable numbers.

Behavorial Observations
The entire colony hunts whatever prey they can find. There does not appear to be any intelligent design behind the choice of prey. They simply attack what is closest and most vulnerable. Livestock and young humanoids often fit this criteria.

Their hunting grounds are usually only 2 miles around the colony. Once an area is drained, they move on, making finding the nests, to destroy them, very difficult for terrified locals.

Intra-Species Observations
Stirge are mostly a lone species. They are feared by most creatures without a very thick hide to stave off their predations. One of the exception is the Dragon ( Draco draconis ). A dragon's hide is completely impenetrable to the stirge, and they are often found in or near dragon lairs. The dragon allows this because the stirge are simply the most efficient and alert organisms at keeping the curious (accidental or intentional) at bay.

Stirge have also been seen with Umber Hulks, Quaggoth, and Purple Worms. They are found throughout the Underdark, and in any surface area that affords a safe haven - caves, attics, ancient forests, ruins, even on the hulks of wrecked sailing ships.

Variant Species
Stirge have thrived and adapted to almost every climate. Some of these species have been directly observed and some have only been the subject of rumor or debate.
 * Jungle Stirge thrive in the hot, steamy climates of jungles. They have evolved a paralytic toxin that they inject into their victims that leaves them unable to move until the stirge have all fed, or the victim is completely drained.
 * Artic Stirge have furred legs and thicker wings. They are camouflaged with mottled patterns that appears as rock and snow. They are larger than normal stirge, with a 4-foot wingspan and nearly twice the body size. They naturally take more blood from their victims as well.
 * Desert Stirge are especially feared. They nest in the sands and ambush victims that walk over their colony lairs. They are smaller than normal stirge, and feed less, but their colonies are almost 4 times the size of a normal stirge.
 * Sleep Stirge have been warped by exposure to wild magic energies and can induce sleep (as the mage spell) in their victims as a collective group, and at increased power. These so-called Dozy Stirge have been observed employing arcane energies equal to a magic-user that has achieved the 5th level of mastery in their Guilds, and have taken down nearly 30 humanoids at one time.
 * Invisible Stirge are the subject of much debate, and most reputable scholars and adventurers refuse to believe such tales, attributing the drained corpses found in some dungeons and old lairs to undead or other parasites.