Bumblebees Enjoy the Taste of Sugar
Dawn Monrose/Alamy
Recent studies indicate that bees display preferences beyond mere survival needs, suggesting a subjective experience akin to emotion. This groundbreaking discovery may alter our understanding of insect cognition.
While bees have previously demonstrated complex behaviors—such as counting and sensing rhythm—figuring out their emotional states has been challenging, as insects lack the nuanced facial expressions found in mammals.
“How do we interpret the behaviors of these hard-bodied insects with limited facial expressions?” questions Andrew Barron from Macquarie University in Sydney. “Do these bees experience internal states?”
To delve deeper, Barron and his team designed experiments involving buff-tailed bumblebees (Bombus terrestris).
The researchers provided the bees with sugary water droplets, alongside salty and bitter solutions, capturing their reactions on high-resolution video.
After tasting the sugar solution, bees exhibited frequent glossa extensions (the hairy tongue they use for nectar). Contrastingly, when presented with salty or bitter options, they responded by wiping their mouths and shaking their heads.
Bee Wiping Its Mouth
Southern Medical University Honey Bee Laboratory
Barron noted that these reactions might not directly indicate enjoyment; they could simply reflect responses to various chemicals.
The researchers then adjusted the sugar concentration, combining it with a bit of salt, which significantly reduced glossa extensions. Additionally, they exposed the bees to high temperatures (40°C/104°F) to mimic dehydration and then offered salty droplets, prompting them to poke out their glossa.
“Consider this: if I offered you an electrolyte drink after a heavy workout, you’d likely find it appealing. The internal state influences your perception,” Barron explains.
Bee Sticking Out Glossa
Southern Medical University Honey Bee Laboratory
In the final phase of the experiment, researchers sought to manipulate the chemistry associated with appetite and satisfaction in mammals.
When bumblebees received dopamine—known to influence motivation in mammals—their glossa protrusion remained unchanged, indicating a disconnect between desire and pleasure.
Conversely, administering endocannabinoids to honeybees, which enhance food enjoyment in mammals, led to increased glossa extensions.
“This suggests that insects like bees possess an internal life, evaluating and interpreting their surroundings. They are not simply automata adhering to preprogrammed responses,” Barron adds.
Ralph Adolphs from the California Institute of Technology highlights the study’s significance. “It showcases innovative research addressing a challenging subject,” he states, acknowledging the evidence supporting flexible behavioral responses in bees toward taste stimuli.
However, he questions if such evidence equates to the pleasure as humans understand it: “Facial expressions alone do not define emotions; people with facial paralysis also experience feelings,” he remarks. “One must conclude that bees may have their own unique emotional experiences, distinct from mammalian ones.”
Jonathan Birch from the London School of Economics noted this study was the first to untangle the bees’ “wants” from their “likes.” He concludes, “We often underestimate insects. We’re entering a fascinating era of research where advanced techniques reveal unnoticed behaviors, as evidenced in this study.”
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Source: www.newscientist.com
