Can wasps smell fear?

[JoeTheJuggler]

Fear is an emotion, not a molecule. So wasps (and dogs) definitely cannot smell fear.

Whether they can sense fear by smelling sweat or something in sweat or through some other means is the question I think you're after. (Even if you establish that wasps react to the presence of more or less sweat, you still have to find out whether they can distinguish fear-induced sweat from any other sweat even to say they can "sense fear".)

 

[illogical]

i'd imagine they are attracted to fear in that nervous people make rapid movements and sweat too much.

i've noticed that tobacco smoke and glasses attract them too. both cause movement, so they investigate.

 

[illogical]

Watching someone flail at a wasp always reminds me of Jim Furyk taking a golf swing.

we have a lot of hornets or hornet-like wasps here. i wish i could find some way to keep them off the porch. spiders and wasps aren't affected by the pesticides we use.

i love spiders although they have left wounds that last for months.

 

[Cuddles]

Ah, well, maybe this can be another reason why wasps seem to be attracted to people who start flailing their arms.

Hmm, apparently what I forgot to put at the end is that I'm fairly sure that waving your arms won't produce a strong enough effect to make wasps hit you, considering that they are quite happy flying in winds much stronger than this. Especially since it is quite a short range effect, so any wasp affected must already be right next to you.

 

[Humphreys]

Especially since it is quite a short range effect, so any wasp affected must already be right next to you.

Well yeah, that's what I assumed.

Wasp flies near person, person flails arms, wasp can't get away from crazy flailing arms person because of vacuum created.

Personally, I don't really buy it as a significant factor. I think the chaos created by someone going crazy makes the wasp think it's in danger, and makes it panic and attempt to fight back.

 

[Sir Arthur Mortal Coyle]

From my brother who's an enthusiastic entomologist :


Acetic acid and isobutanol has been used successfully as a wasp attractant for baited traps. Acetic acid gives vinegar its smell and is a product of fermentation of fruit etc. Isobutanol is also considered an alcohol, and again forms part of the fermentation/breakdown of organic matter. Wasps are attracted to these because they often feed on decaying plant and animal matter.

Acetic acid is also produced by humans/primates as a sort of antibacterial agent in certain parts of the body (especially female 'bits') not to mention other forms of bacteria. Yeasts etc all over us. Also it’s likely that we often have these chemicals around/on us as we're constantly handling foodstuffs or liquids like beer/wine etc.

I've mentioned before that certain deodorants/perfumes etc contain certain chemicals that attract/upset wasps. Some research is going into this to remove the chemical attractants and so reduce wasp 'encounters'.

As far as pheromones go, if a wasp feels in danger it gives off certain pheromones that warn its kin. But you'd have to be near a nest for it to affect other wasps and so possibly promote multiple attacks.

So in the end all the wasp is doing is following its 'nose' looking for food, but all it finds is a great big colourful smelly thing threatening it with wavy arms!

 

[Ichneumonwasp]

Can wasps smell fear?

Why, yes, we can.

 

[Puppycow]

Once I was picnicing and I spilled some soda. That really attracted them. If you ate or drank anything recently they could simply be smelling the food on your breath.

I doubt that what they smell is 'fear'

 

[steenkh]

I thought it was our CO2 exhaust that they sensed as a threat.

I once saw on TV how a man could disturb a nest of wasps if he breathed into a pipe that led the exhaust away. It seems that when wasps are disturbed they produce a pheromone that makes them aggressive, and then they attack anything that breathes CO2. If we are scared we probably breathe more heavily, and attract more attacks.

 

[Soapy Sam]

More anecdotes!!

When I wear highly-perfumed hairspray, wasps men can't keep away.

A few years ago I was convinced that wasps men were more attracted to me when I wore certain colours of clothing (purple, for example), but I'm not sure how much sense that makes. I was thinking bright clothes = flowers.

Fixed.

 

[Modified]

A few years ago I was convinced that wasps were more attracted to me when I wore certain colours of clothing (purple, for example), but I'm not sure how much sense that makes. I was thinking bright clothes = flowers.

Could be. I had a bag of potting soil with pictures of flowers on it, and the carpenter bees kept attempting to visit those flowers.

 

[illogical]

personally, I don't really buy it as a significant factor. I think the chaos created by someone going crazy makes the wasp think it's in danger, and makes it panic and attempt to fight back.

yes, i believe some of the deaths are from people flipping out and a swarm attacking them. obviously, anaphylatic shock and playing with the nest are dangerous too.

they are all over the American South and i've never been stung down here. the fire ants have moved within 20 miles of here, but no "africanized" honey bees.

 

[baron]

Even if wasps could detect fear, why would they approach people who exhibited it? I can't think of how they would benefit from this behaviour.

However, if they do I wholly approve of it. A workmate of mine, on noticing a wasp approach, threw his coffee at it and fell off his chair. He then ran into my desk and knocked my coffee over before trying to kick the wasp and running from the room. I was desperately disappointed when he failed to get stung.

 

[steenkh]

Could be. I had a bag of potting soil with pictures of flowers on it, and the carpenter bees kept attempting to visit those flowers.

Wasps are not bees, they do not collect pollen, and they are not attracted to flowers.

 

[kellyb]

Wasps are not bees, they do not collect pollen, and they are not attracted to flowers.

Quick google search says wasps actually do drink nectar sometimes:

http://www.madsci.org/posts/archives/dec96/848347319.Gb.r.html

Some paper wasps drink nectar from flowers. But most paper wasps have special eating habits. These eating habits are special because all the wasps in the nest share food.

Adult paper wasps either drink nectar or catch caterpillars and drink the caterpillar's blood, or hemolymph. Then the adult wasp flies back to the nest and regurgitates (throws up) the nectar or blood into the mouths of young (larval) wasps or other adult wasps. After the young wasps are full, they produce a saliva (or spit) which is fifty times more nutritious than nectar. The adult wasps drink this saliva from the mouths of the young wasps.

ETA:
Drinking nectar and collecting pollen being different things, of course.

 

[steenkh]

OK, I bow to the evidence. I have, however, never seen a wasp on a flower.

 

[kellyb]

OK, I bow to the evidence. I have, however, never seen a wasp on a flower.

I haven't either. Your post highlighted the fact that I'd never heard of exactly what wasps eat, though. And apparently it's nectar. Whodathunkit.

Come to think of it, I think I might have seen wasps hovering in clover patches before. I guess I always figured they were hunting ants or something.

 

[steenkh]

I haven't either. Your post highlighted the fact that I'd never heard of exactly what wasps eat, though. And apparently it's nectar. Whodathunkit.

As far as I know, they are mainly predators, although when their young have left the nest, they go for the sugary things that they like best, which is why we find them hunting pastry and drowning in soft drinks in the late summer. And they would probably go for the nectar at that time also.

I once watched a number of wasps cutting pieces off the ham in a ham sandwich, carrying them back home, and returning for more ham. they also liked liver paté. Definitely not vegetarian.

Besides, I am not entirely sure if we are always discussing exactly the same species of wasps, and if they all have the same habits.