Cover Image: January 2012 Scientific American Magazine See Inside

Bees Appear to Experience Moods

Provocative experiments suggest that insects have something resembling emotions














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In the initial setup of Bateson’s experiment, a group of honeybees was trained to associate two simple odor mixtures with two different foods. One mixture, which consisted of one part hexanol to nine parts octanone, was repeatedly paired with sucrose, which bees find rewarding. The other odor mixture consisted of the same two chemicals in opposite proportions (nine parts hexanol to one part octanone) paired with quinine, a compound that most of us find bitter and bees will actively avoid after tasting. By using this technique, the researchers hoped to overcome the bees’ intrinsic responses to sucrose and quinine and test only their judgment of the new smells. After learning these odor-food associations, the bees responded as expected, uncoiling and extending their mouthparts in anticipation of food when the first odor mixture was presented and retracting them at offers of the second concoction.

This training allowed the scientists to study the bees’ decision making by then testing their mouthing responses to a series of ambiguous odor mixtures. First, half the bees got a trip to the “vortexer.” The experience was probably as unpleasant for them as it sounds to us. In a procedure meant to simulate a badger attack on a hive, the bees were shaken for one minute in a machine typically used to vigorously mix chemicals. If bees can indeed be made to feel cranky, surely this device would do the trick.

Next, both shaken and unshaken bees were tested on five mixtures of hexanol and octanone at different concentrations. Sure enough, both groups preferred extending their mouth to octanone-heavy mixtures, which predicted sugar, rather than hexanol-heavy mixtures, the scent of which predicted quinine. Interestingly, the shaken bees were less likely to advance toward any of the mixtures than their unperturbed counterparts.

In an analogue of the classic scenario  of the half-empty glass versus the half-full glass, the bees were also presented with an equal mixture of hexanol and octanone. Bees that were spared the trip to the vortexer gave the concoction the benefit of the doubt, moving their mouth toward the food on close to 60 percent of the trials. Shaken bees, on the other hand, ignored or recoiled from these same ambiguous stimuli more than half the time. The stress of shaking had turned them into pessimists that interpreted the ambiguous odor as half threatening rather than half appetizing.

Both Shaken and Stirred
In addition to these behavioral measures, the scientists also tested for changes in the bees’ neurotransmitter levels after shaking. The quantities of certain chemicals with known roles in insect learning (octopamine), aversive conditioning (dopamine) and aggression (serotonin) were all reduced by the procedure, suggesting that as with their mammalian counterparts, duress in bees causes sustained, system-wide changes in brain state—a possible analogue of mood. Together these behavioral and neurochemical tests reveal an unexpected dimension of bee cognition. Formally, we can say that when agitated, bees can take on a negative disposition, a state that alters both their thinking and their neurochemistry.

For now, however, we cannot conclude anything more sweeping about the emotional life of a bee. Bateson and her co-authors leave us with an intriguing plea for consistency, however, one that nudges us to think clearly about how we regard the minds and emotions of all creatures. Last year researchers tested dogs that appeared to suffer from separation anxiety for a pessimistic bias. When they encountered an uncertain food reward, the perturbed dogs also appeared less inclined to try the ambiguous treat, which the researchers interpreted as evidence that dogs indeed feel anxious when left alone. “It is logically inconsistent,” Bateson and her colleagues say, to deduce that dogs and other similar animals express emotions “but to deny the same conclusion in the case of honeybees.”


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  1. 1. Carlyle in reply to IC 01:55 AM 12/27/11

    What is more, during hard times, they are kicked out of the hives & never having been taught to fend for themselves, they starve.

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  2. 2. Carlyle 01:59 AM 12/27/11

    Any beekeeper can tell you, they most definitely experience moods. 99% or more are frustrated females by the way :).

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  3. 3. Kymii 10:49 AM 12/27/11

    Imagine that!A living breathing creature has emotions lol ...Humans never cease to amaze me with their superiority complex.

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  4. 4. Elegia 11:08 AM 12/27/11

    Ah, the tiny note in the abandoned hive may now be deciphered.

    "Tired of the queen replacement thing. So long, & thanks for all the pollen."

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  5. 5. Elegia in reply to Kymii 11:09 AM 12/27/11

    Well said! :)

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  6. 6. David N'Gog 12:15 PM 12/27/11

    The typical argument against animal emotions is that we can't prove their actions are not evolved response systems.

    Using that logic, we've never actually proven that humans have emotions.

    I know I have them- but how do I know that everyone else just doesn't have evolved response systems.

    That said, it IS easier to recognise that animals more similar to ourselves have emotions than those dissimilar- and perhaps this skepticism is a correct response- we shouldn't make assumptions that two distantly related organisms behave the same way.

    I do hope we all will try to be good to all animals though. Give them the benefit of the doubt- that they could, and probably do have emotion- even bugs.

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  7. 7. IR2D2 12:22 PM 12/27/11

    Check out this app to learn why bees and insects are critical for the plant lifecycle
    http://bitly.com/vfUWTU

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  8. 8. tharter in reply to David N'Gog 12:24 PM 12/27/11

    Yeah, basically it boils down to the whole "what is consciousness" question. Probably not something that can ever be addressed by any type of logic or observation. In fact I would say that these types of questions lack validity.

    All we can probably ultimately say is that our own theories of mind have some level of applicability to bees etc. Not really surprising as other posters have said.

    More interesting questions might be to what degree we share the same neurophysiology in this regard. That kind of information has real utility.

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  9. 9. Carlyle in reply to Carlyle 07:25 PM 12/27/11

    The first two posts have been deleted. Without one of them, my first post does not make sense. The deleted post referred to the drone bees. The male bee. The fact that they have no status or duties was jocularly referred to.

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  10. 10. cogitabundus 05:38 AM 12/28/11

    "The stress of shaking had turned them into pessimists that interpreted the ambiguous odor as half threatening rather than half appetizing." Was it really affective stress or some physiological stress/disorientation like vertigo that makes one uninterested in, or perhaps even unable, to fully sense and approach pleasurable stimuli? When I emerge from the whirling carnival ride, is that the same affective state as when I am worrying about my responsibilities, relationships, survival, etc.? The result of the carnival ride may be stress insofar as my sensory experience and neural correlates have been altered, and I'm having a different, uncomfortable, experience. That seems to be a different experience than the affective anthropomorphic pessimism/stress that this article wonders about our little friends of all kinds having. Does that make sense?

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  11. 11. tharter in reply to cogitabundus 09:14 AM 12/28/11

    I think the question would be how long it lasts. Maybe also what happens when you subject bees to other stresses or repeated stresses.

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  12. 12. verdai 06:30 PM 1/4/12

    O Fine, -
    the things that have emotion(s) are growing in numbers among men.
    my tree and my stone also have them, but not the same way: something like the wind.

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