We slap bees to avoid painful stings, but do they feel pain us cause? A new study suggests they do, which may be a clue that they and other insects have sentience — the ability to be aware of their own feelings.
Philosopher and animal perception expert Jonathan Birch of the London School of Economics, who was not involved in the paper, said: “It’s an impressive piece of work” with important implications. If the study holds true, he said, “there are far more beings in the world than we think.”
Previous research has shown that bees and bumblebees are intelligent, innovative creatures. They understand the concept of zero, can do simple math, and can differentiate between human faces (and possibly bee faces). They are usually optimistic when they are successfully foraging, but can become depressed if temporarily trapped by a predatory spider. Even if the bee escapes the spider, “her behavior changes; after a few days, she’s afraid of every flower,” says Lars Chittka, a cognitive scientist at Queen Mary University of London, whose lab carried out the study and this new research. “They’re going through an emotional state.”
To find out whether these emotions included pain, Chitka and his colleagues looked at a standard commonly used to define pain in animals: “motivational tradeoffs.” For example, people endure the pain of a dentist’s drill for the long-term benefit of healthy teeth. Likewise, hermit crabs only leave their favorite shells to escape shocks when subjected to particularly high vibrations—an experiment that shows crabs can distinguish between weak and strong painful stimuli and decide how much pain is worth it. This suggests that crabs do feel pain and do not simply respond reflexively to unpleasant stimuli. Thanks in part to this research, crabs (and other crustaceans, including lobsters and crayfish) are considered sentient under British law.
Chittka’s team presented 41 bumblebees (bumblebee) choose between two premium feeders with a 40% sugar solution and two feeders with a lower percentage of sucrose. The researchers placed the feeders on the test field on top of individual heating pads in pink or yellow. Initially, all heating pads were turned off; bees entered the arena one at a time to sample the feeders. They had to sip from each one to test the sugar content. All people love the most sugary feeder.
The scientists then heated the yellow pads beneath the two high-sucrose feeders to 55°C (hot enough for the bees to consider leaving, but not high enough to cause harm); the feeders on the pink pads stayed cool. For a bee, landing on a hot yellow pad is like us “touching a hot plate,” says lead author Matilda Ross Gibbons, a behavioral neuroscientist and Ph.D. Students in Chittka’s lab. But bees that can take the pain also get more sugar.
scientists today Proceedings of the National Academy of Sciences“If the sugar was super concentrated, the bees would suffer more,” Gibbons said. “They could walk away at any time, but they didn’t. Getting sugar was a huge motivator.” The scientists report that when both the hot and cold food containers were filled with a high-sugar solution, the bees avoided those on the yellow mats— This suggests that they used associative memory when choosing where to feed.
In addition to crustaceans, “this is the first direct demonstration that arthropods” — a group that also includes insects and spiders — “also have trade-offs,” Birch said. He called the research “intellectually fascinating” and “ethically important” given the growing interest in farming insects for human consumption and the complete lack of “studies on insect welfare needs.”
Still, it remains unclear whether bees actually feel what we call pain. The scientists noted that their study did not provide “formal evidence” of this ability. Given its subjectivity, “it may be impossible to prove that insects feel pain,” said Greg Neely, a behavioural geneticist at the University of Sydney.He has shown that the nervous system of fruit flies experiences chronic painbut he doubts that insects have nervous systems that allow pain to register as a complex emotion.
Jennifer Mather, a zoologist and cephalopod expert at the University of Lethbridge, agrees that it may be impossible to definitively prove that insects feel pain mentally, and his research has helped prove that these animals do. Felt. Still, given that insects make up at least 60 percent of all animals, she said, “we cannot ignore them. There is still anthropocentrism in Western science that refuses to care about ‘dumb invertebrates’. Papers like this would undercut this Self-centered attitude.”
Update, July 27, 2pm:This story has been updated to clarify that the experiment did not harm the bees