Raindrops Keep Falling on My Head

June 27, 2015 8:19 AM

a mosquito being hit by a raindrop is roughly the equivalent of a human being whacked by a school bus, the typical bus being about 50 times the mass of a person. And worse, when it’s raining hard, each mosquito should expect to get smacked, grazed, or shoved by a raindrop every 25 seconds. So rain should be dangerous to a mosquito. And yet

why aren't mosquitos hurt or killed by raindrops?
posted by MartinWisse (46 comments total)

I've been updating my yo mama jokes every since I read this article.
posted by Foci for Analysis at 8:27 AM on June 27, 2015 [1 favorite]

Such a shame.
posted by vanar sena at 8:29 AM on June 27, 2015 [6 favorites]

Fascinating. This is a perfect example of 'go with the flow.'
posted by LeLiLo at 8:34 AM on June 27, 2015 [1 favorite]

Mosquito Chamber, dibs on new band name.
posted by Dee Grim at 8:48 AM on June 27, 2015 [1 favorite]

Now I'm switching from the adage "walk between the raindrops" to "ride a raindrop for awhile and then casually step to the side."
posted by RobotVoodooPower at 8:50 AM on June 27, 2015 [7 favorites]

This knowledge will come in handy during my camping trip next weekend, which, based on the amount of rain we've had this spring (lots) and the long-term forecast at the moment (more rain!), I expect to feature lots of both rain and mosquitoes.
posted by The Card Cheat at 8:54 AM on June 27, 2015

Scale comparisons in animals (spiders can lift X* their weight, fleas can jump X* their height, mosquitoes can survive an impact with a raindrop 50* their mass) are inappropriate and misleading. They have muscle cells the same size as our muscle cells, they have a very low weight due to volume scaling with the cube of size. The "superpower" is not some superior scale-invariant design, it's a side effect of being small.
posted by idiopath at 9:05 AM on June 27, 2015 [43 favorites]

If rain really was God crying (perhaps over having inadvertently creating mosquitos), those little bloodsuckers wouldn't have a chance. Not feeling my usual Darwin-love this morning.
posted by kozad at 9:09 AM on June 27, 2015 [3 favorites]

See, this is something I've never fully understood. At some point, don't the ABSOLUTE levels of force matter? In other words, if a bug falls from a height of a few feet, we expect it to be unscathed, even though from the bug's perspective that's like falling from a skyscraper. Because the absolute level of force when it hits the ground from a few feet is not very much. The raindrop itself has a lot of mass relative to the mosquito, so it can move it, but I wouldn't expect the impact of the raindrop and the mosquito to actually HURT it. But then again I know basically nothing about physics and how impacts work.
posted by pravit at 9:17 AM on June 27, 2015 [1 favorite]

I swear I read this as:

why aren't mosquitos hurt or killed by raptors raindrops?

And I was thinking to myself, those would have to be some big ass mosquitoes! An entirely different kind of National Geographic article.
posted by Fizz at 9:29 AM on June 27, 2015 [1 favorite]

Fuck you for not trying harder, rain.
posted by Artw at 9:41 AM on June 27, 2015 [37 favorites]

Hmmm. Maybe there's something to this inertia business...
posted by mondo dentro at 9:45 AM on June 27, 2015 [1 favorite]

Now lets observe how Mosquitoes deal with flamethrowers!
posted by blue_beetle at 9:48 AM on June 27, 2015 [20 favorites]

pravit: a smaller creature can survive a fall from a greater height. Humans can survive falls that would kill an elephant, spiders can survive falls that would kill a human. A big part of this is that the thing doing the injury on impact is the faller's own mass crushing it (which as mentioned above scales with the cube of size - it blows up very fast).
posted by idiopath at 9:49 AM on June 27, 2015 [2 favorites]

So the obvious next step for science is to develop raindrops that are lethal to mosquitos.
posted by Salvor Hardin at 9:53 AM on June 27, 2015 [7 favorites]

Meanwhile, it's been raining so much here that the mosquitoes are breeding like mad in every standing puddle of water.
posted by octothorpe at 10:21 AM on June 27, 2015

Mosquitoes are fabulously well-engineered in every detail and at all levels of magnification.

If mosquitoes had consciousness, a collective consciousness say, it would see taking blood as an act of worship of its great hot lumbering gods, and the tremendous toll we take of them as a sacred sacrifice.
posted by jamjam at 10:23 AM on June 27, 2015 [15 favorites]

I was gonna say "uh wow creepy who would EAT the flesh and DRINK the blood of their gods" and then I remembered.
posted by poffin boffin at 10:27 AM on June 27, 2015 [38 favorites]

pravit, you might like the essay Size and Shape by Stephen Jay Gould, which discusses that while it's relative levels, not absolute levels, that matter, different quantities (weight, strength, etc.) grow at different rates and this makes animals at different scales face different problems and come up with different solutions.
posted by benito.strauss at 10:34 AM on June 27, 2015 [10 favorites]

So the obvious next step for science is to develop raindrops that are lethal to mosquitos.

Or mosquitos with more mass.
posted by Greg_Ace at 10:57 AM on June 27, 2015 [2 favorites]

Yo, fuck mosquitoes though.
posted by Cookiebastard at 11:00 AM on June 27, 2015 [4 favorites]

Hey now mosquitoes are people too
posted by unknownmosquito at 11:09 AM on June 27, 2015 [2 favorites]

...you might like the essay Size and Shape by Stephen Jay Gould, which discusses ... [how] different quantities (weight, strength, etc.) grow at different rates and this makes animals at different scales face different problems...

If you find this sort of thing fascinating (the physical and geometrical foundations of biomorphology), there's also the beautiful classic by D'Arcy Thompson, On Growth and Form. You can pick up a used paperback online for a few bucks.
posted by mondo dentro at 11:09 AM on June 27, 2015 [4 favorites]

So the obvious next step for science is to develop raindrops that are lethal to mosquitos.

Yeah. Like acid rain!

Oh, wait...
posted by mondo dentro at 11:13 AM on June 27, 2015

Or mosquitos with more mass.

Just enough so they can't fly and instead have to walk up to your shin and politely request to bite you.
posted by shakespeherian at 11:38 AM on June 27, 2015 [5 favorites]

Congratulations. You've just invented the tick!
posted by mondo dentro at 12:14 PM on June 27, 2015 [36 favorites]

There is a lot of counterintuitive stuff that happens when you switch size scales away from what we're used to experiencing. There's another one that pertains to mosquitos: they can't handle light wind.

The issue here is that a few mph wind isn't much in terms of energy or force, but that wind is turbulent. If you're person-sized, you don't notice the turbulence much, but a mosquito feels every centimeter-sized turbulent eddy, and these eddies have small scale velocities much in excess of the bulk velocity we humans would feel. Plus when you're small and have a large wing, it doesn't take much force to cause significant acceleration. (This is why oscillating fans are an effective means of keeping insects away.)
posted by kiltedtaco at 12:24 PM on June 27, 2015 [4 favorites]

I was gonna say "uh wow creepy who would EAT the flesh and DRINK the blood of their gods" and then I remembered.

Yep, mosquitos with more Mass.
posted by wilko at 12:28 PM on June 27, 2015 [27 favorites]

benito.strauss: thanks for the citation, it was the source I had forgotten years ago about this size scale stuff
posted by idiopath at 2:28 PM on June 27, 2015 [1 favorite]

Isn't this similar to what makes the small superheroes (Ant-Man, the Atom, the Wasp, etc) so effective? They shrink down to tiny sizes but keep their strength. So they can jump far and punch really hard from inside the thing they're fighting.
posted by any portmanteau in a storm at 2:29 PM on June 27, 2015

Georgia Tech? He should be studying Yellowjackets!
posted by TedW at 3:05 PM on June 27, 2015 [2 favorites]

I just want to point out that even a short schoolbus masses well over a hundred times what an average adult human does. Fifty times would be more like, say, a Cadillac Escalade. And who among us hasn't been through a few Escalade Rains in their days?
posted by Anticipation Of A New Lover's Arrival, The at 3:20 PM on June 27, 2015

Maybe it's just because they are busy walking out of the raindrops, but as a person who is a delicacy to mosquitoes, I have found that I almost never am bitten while it is raining.
posted by wierdo at 3:39 PM on June 27, 2015

Just the other day I was trying to think about the concept of any benefit that mosquitoes provide to nature besides being food for bats, birds, frogs, spiders or other larger creatures, and the only thing I could think of is that they might help cause some genetic cross-pollination or disease resistances and such by spreading bacteria and viruses around.

On a completely different tangent there's an art installation project I've been toying with for about a year, intended for an outdoor art fest called Lo Fi at Smoke Farm in Washington, where there have been too many damn mosquitoes.

The installation would involve some form of a lit and a mosquito attractant (perhaps carbon dioxide being selectively dispersed in a pattern) to to spell out something like "COME CLOSER" in 10 foot tall letters using nothing but mosquitoes.
posted by loquacious at 5:46 PM on June 27, 2015 [4 favorites]

Maybe it's just because they are busy walking out of the raindrops, but as a person who is a delicacy to mosquitoes, I have found that I almost never am bitten while it is raining.

Perhaps they are otherwise occupied. I would think that insofar as a mosquito perceives the air, it is as a neutral medium to traverse, the way you or I might view flat ground. In the midst of an earthquake with the ground rippling like ocean waves, I would likely also to be distracted to eat.
posted by ricochet biscuit at 6:22 PM on June 27, 2015 [1 favorite]

...a smaller creature can survive a fall from a greater height.

My understanding is that terminal velocity plays a big part in this. A mosquito is so light that it won't actually fall very fast due to air resistance.

Isn't this similar to what makes the small superheroes (Ant-Man, the Atom, the Wasp, etc) so effective?

Pretty sure that's just comic book nonsense?
posted by buriednexttoyou at 6:26 PM on June 27, 2015 [1 favorite]

In addition to the Stephen Jay Gould and D'Arcy Thompson recommendations above, I'd recommend Why Elephants Have Big Ears, by Chris Lavers.
posted by cardioid at 6:28 PM on June 27, 2015 [1 favorite]

A few weeks ago I found a spider in my house, so I thought I would be a Good Person and take it outside. So I took it out to the balcony and tried to put it on the leaf of a nearby tree. But it immediately fell off the leaf. I felt so bad about this stupid spider. This thread is making me feel better that perhaps I didn't kill it after all? (Please just let me live with this delusion, if it is one.)
posted by bleep at 7:45 PM on June 27, 2015

The installation would involve some form of a lit and a mosquito attractant (perhaps carbon dioxide being selectively dispersed in a pattern) to to spell out something like "COME CLOSER" in 10 foot tall letters using nothing but mosquitoes.

This is terrifying and delicious and PLEASE DO IT.
posted by Ragini at 11:31 PM on June 27, 2015 [1 favorite]

I agree with a lot of earlier posts that mass and absolute force matter. A human at 300 g gets 28,000 mosquito-raindrops of force. A typical sports concussion is 100g.
posted by CBrachyrhynchos at 11:44 PM on June 27, 2015 [1 favorite]

But remember, even though they can detach themselves from raindrops, this does not mean that they like raindrops. As anyone who has been in a torrential downpour in a swamp, you might cover your head with a rain bonnet or hat. And maybe angle your head down to keep the pelting rain off of your face, make a small air pocket. And you would find yourself in that little air pocket along with hundreds of annoyed mosquitoes who are trying to avoid the rain as well. No doubt inhaling and perhaps swallowing a few at the same time. But fear not. They will make a meal of you as well.

Circle of life,baby. Mufuggin' circle of life.
posted by Splunge at 2:23 AM on June 28, 2015 [2 favorites]

So the obvious next step for science is to develop raindrops that are lethal to mosquitos.

There was one condition when they were. From the original paper: Mosquitoes may experience life-threatening impacts if flying very low to the ground. Without sufficient distance to recover from impact, the insect could strike the ground with the speed of a falling drop or be immersed in pools of water from which it cannot escape. Such an effect was evidenced in our jet and drop chamber experiments. A mosquito which landed into a puddle ultimately perished, not from the impact of drops, but by drowning due to adhesion of its body with the water surface. Although the insect is covered in water-repellent hairs, these hairs do not seem to confer any advantage with respect to the force imparted.

Makes you wonder whether mosquitoes avoid water when it's raining, and whether, by extension, staying in the water during the rain might be a way of avoiding being bitten.
posted by kisch mokusch at 3:15 AM on June 28, 2015

I've definitely been bitten by mosquitoes while out in the rain. In fact, I've had my face bitten by mosquitoes while I was neck-deep in a lake in the rain, mere inches above the deadly water surface where they could drown if a raindrop hits them. I guess the mosquitoes haven't read this paper yet, or they'd know to stay up high when it's raining.

I wish there was video of them walking sideways off the raindrop. That sounded cool.
posted by vytae at 9:00 AM on June 28, 2015 [1 favorite]

This is not that video.
posted by Too-Ticky at 9:18 AM on June 28, 2015

buriednexttoyou: "Pretty sure that's just comic book nonsense?"

Sadly the literature is lacking in examples of real life people who can turn into insects.
posted by Mitheral at 6:52 PM on June 30, 2015

A lot of biological process scale with cross section (x²), while mass scales with volume (x³). So all things being equal, Ant Man's muscles will have a higher power/weight ratio at 1/100 scale than at full size. However, small muscles mean less total power, so he wouldn't be able to do much more than jump into your face and tickle you with an ant-powered punch.

This is neglecting the fact that his entire body evolved and developed for the height and weight of a healthy adult. The timing of sensory feedback would be completely wrong. He might be blind and deaf as his eyes and ears shrink but the wavelengths of sound and light does not. Joints, tendons, and ligaments may scale down in ways that are painful. He'd have some problems with basic chemistry unless he carried his own shrunken oxygen supply.
posted by CBrachyrhynchos at 8:44 PM on June 30, 2015