The result of your average small house centipede isn't horrendous. Its the big bastards, Scolopendra spp. that will leave people screaming. Some of those grow up to a foot in length, give or take a bit either way. And the venom of those things is pretty powerful. Seen footage once of a giant cave centipede hanging with half its body onto a cave roof, and with the other half, snatching a bat out of the air, the bat was dead in maybe 15-20 seconds.
Most unlikely to kill a healthy adult human, although capable of killing young children (the really large kinds, not house centipedes) but from what I've heard about getting nipped by one, they REALLY hurt. And they aren't shy in the least about doing it either.
Also apparently, giant centipedes are very, very strong for an invertebrate. I have read in some documentary-film-style books covering them that handling a giant centipede is much closer to wrestling with a small python (I.e of not greatly larger size than the centipede) than it is to trying to hold any other insect. lightening quick, damn bad tempered and unlike a snake they won't give a warning if they get pissed off, they will just go for it and 'bite' (what look like fangs, aren't true jaws, the poison delivery apparatus of centipedes rather, is a modified pair of front legs which serve the same purpose as snake/spider fangs)
And from that docu I saw...fucking hell they have a fast strike too, the giant cave centipede taking the bat, was too quick to follow with the eye, one moment hanging around, the next, munching on a now dead bat it had just plucked from the air.
And here, some interesting trivia (although very, VERY unlikely to become a pest in, or even to enter a house)
https://en.wikipedia.org/wiki/Scolopendra_cataracta Up to almost 10 inches long, not huge for a giant centipede, but this species is at least partially aquatic, scurrying along the bottom of riverbeds in its native environment (southeast asia) and reportedly, even swimming, like an eel, according to the wikipedia article. This would make it the only (known) centipede species to be aquatic.
Aside from one other, Scolopendra weebliphagus, from the greek 'ουβλ' (a rounded, jolly, eggshaped that wobbles, but which will not fall down' and φαγην' ''phagein' that which eats', these like to live in damp, humid places such as the crevices of toilets, cisterns and taps, where until their prey approaches in the dark (like most centipedes they are nocturnal or diurnal), they rely on their very flexible bodies, to squeeze into small spaces within which to wait, catch their prey and suck its juicy guts out) and once detecting their ουβλ victim, out they come, through the U-bend and snatch it, dragging it down into the sewers to feast at leisure.
In fact, lately, studies have shown, from the piles of ουβλεε bones found down in sewers in close to proximity to the nests of these centipedes, previously thought rare, that they are in fact not, and numbers of both disappearing jolly egg-like creatures that whilst wobblesome, never fall down, curiously, always it seems, at night when the ουβλεε has gone to use the toilet, that numbers of the weebliphagous reallyreally REALLY giant centipede are far bigger than first thought, and what is more, the population size is increasing dramatically. Especially in the US, perhaps due to the availability of prey, sufficient to provide enough juicy ουβλ-guts to sustain themselves and their young, the latter of which like to nest in the ears of developing to middle-aged ουβλ specimens.
Sometimes it is easy to tell when such a midnight attack has taken place, by the occurrence of a hand and wrist, grasping the rim of the toilet bowl from which this unusual kind of centipede has pounced and dragged off the ουβλ prey to consume down in the sewers and provision for any young, which will in time, develop after a period of pupation within the ear canal of (typically, but not always) developing juvenile ουβλ. They have been known to spend their growth phase and undergo metamorphosis to the adult stage within the ears of fully grown adult hosts, after going through the larval stages and preceding the final exit from the host, this centipede species burrows through the ear and enters the skull cavity, inside which it consumes the brain, similar in principle to how spider-hunting wasps of the genera Pepsis and Hemipepsis paralyze spiders and lay eggs on them, the larvae of which burrow within the spider, eating it alive before the adult wasp bursts out), for a final high-calorie meal enabling the young ουβλ-eating centipede to burst out of the skull of the ουβλ husk, like one of those things from the alien movies, the young that hatch from the eggs laid in the chest of the victim by the facehuggers, that eat their way through the chest then burst squealing out of the victim's chest before slithering off to avoid of course, the obligatory missing burst of gunfire if the alien series wasn't going to make for shit movies.
