The ambidroni /ˈæmbidroʊni/ is a light blue stranger with ten to thirteen evenly-spaced, small-footed legs, and a body is composed of a silky, translucent tissue. The eye markings are opaque, and several millimeters thinner than the rest of its body. This form is fragile; any physical contact causes the ambidroni to crumple and collapse, and even faint air currents cause a slight crinkling of the stranger's surface in all but the stillest of rooms.

It casts a dim glow on its surroundings.

When exposed to flame, the ambidroni sizzles and disappears, much like a burning strip of film. This combustion is not hot, however, nor does it spread to even flammable nearby objects.

The vast majority (87.5%) of ambidroni possess a higher-pitched or child-like voice, while the remaining minority speak in a sound resembling white noise.

The ambidroni appears in or near residential areas between sunset and sunrise. It generates indoors 96% of the time, and on rooftops or porches 4% of the time. When it first appears, it fades into view as a crumpled sheet, which rises up to form the ambidroni's shape over the course of 22-35 seconds.

The ambidroni manifests in a group 58% of the time; these "clusters" always appear in a circular or crescent-shaped formations.

An ambidroni will also generate a smaller ambidroni directly beneath it in 3.9% of instances. These "nested" individuals move, live, and die as one unit.^ʗ

The ambidroni's nature is quiet and unassuming. It spends most of its time in a stationary position, its head pointed vertically and its body arched into a tent-like shape. When it moves, it does not lift its legs, but instead, rotates and walks forward using only the tips of its feet, thus keeping its body level.

Rhythmic sounds (such as the ticking of a loud grandfather clock or the dripping of a faucet) cause the stranger to either sway back and forth, or bob up and down,^ɩ and it appears to appears to "dance" in time with music.

Groups of ambidroni do not physically interact with one another, and instead murmur in undulating and circling turns. Five percent of luminderi are able to control the brightness of their luminous bodies, and groups of these individuals dim and glow in slow, patterned waves.

Because the ambidroni is so flimsy, most kill themselves on accident by being caught on a sharp corner, snagged by a moving remote controlled car, or pulled upwards by a sudden gust of wind. When one ambidroni within a group is killed, nearby ambidroni stand over a fallen companion's point of death and whisper amongst themselves.^Ɛ

The ambidroni has some unknown relationship with the moon, and glitters when exposed to moonlight – through an open window, for example, or when a door to a third story emergency exit is left open. This shimmering effect is most noticeable during a full moon, and lost altogether on the night of a new moon.

Animals are of great fascination to the ambidroni. It approaches small animals (such as a book louse or American house spiders) with a playful eagerness, and even pats its toes at cracks in the floor or at the edges of carpets to get them to emerge from a suspected hiding spot. It strokes the surface of these small creatures with careful caresses, and never attempts to grab at or pick them up. The strain displays aggression towards only the smallest of mites and newborn spiders, which it crushes beneath its feet with a happy^Ɐ squint of its eyes.

Despite its observant interest in all creatures, the ambidroni is hesitant towards, and eventually moves away from larger animals (such as an Irish Setter dog, or a two-year-old housecat), as even a single errant swipe of the claws or curious bite can destroy its delicate body.

Though the stranger displays some brief interest in animal corpses, it appears disappointed by their lack of movement, and instead picks at the softest areas of the corpse with lackluster, disheartened^ƿ gestures.

The ambidroni is shy, and though it watches a sensitive from a distance, it retreats when walked towards. This avoidance does not lessen with time; it stops moving only when it hits a corner, and displays no further reactive behaviours once "trapped".^ɖ Despite its socially avoidant response, it does (cautiously) approach a sleeping sensitive, and remains focused on them during the duration of their slumber. Each time the sleeper shifts their position, the ambidroni, in turn, readjusts the its own angle.

Proximity to the ambidroni causes sensitives to cry in their sleep. This effect is harmless, and is not accompanied by unpleasant thoughts or bad dreams.

It is not uncommon for the ambidroni to appear in the bedrooms of individuals who die alone and in bed. When this occurs, the ambidroni manifests upon the bed itself, rather than on the floor. Groups of ambidroni gather in a circular formation, each placing one hand upon the body, and remain observant until the morning.

The ambidroni lives for only a single night. Once the sky begins to lighten, so too does the stranger's body begin to droop, and as the sun's rays pierce over the horizon, it collapses. Its fingers twitch and its limbs struggle to pull itself upward, but eventually, its eye markings crumple inward in serene contentment, and it shrivels into nothing by the light of morning.

Despite this short lifespan, ambidroni infestations tend to repeat night after night, each new cluster oblivious to their predecessors.