A species of blindsnake has been observed decapitating termites, then feeding on the thorax and abdomen before discarding the heads.
The practice is bizarre, even for snakes, which generally like to consume their prey whole -- and alive. However, the authors behind a Journal of Zoology paper on the find, Takafumi Mizuno and Yosuke Kojima of the Kyoto Institute of Technology in Japan, point out that there are already several high profile gross-out snakes with which the typhlopid blindsnake (Indotyphlops braminus) is in competition.
Two species of Asian crab-eating snakes, for instance, have a predilection for ripping off their prey's legs and devouring them one at a time, before consuming the body. But that just seems like good practice: the crabs are too large to ingest whole, without a little leg work. Another two species of leptotyphlopid blindsnakes are also known to break off the heads of termites: then suck out their abdominal contents.
Mizuno and Kojima decided to see if the typhlopid blindsnake could top that. In their trial, they found 47 percent of termites eaten by the test subjects were decapitated. Mizuno told BBC Earth the decapitation rate may just be down to the whole process proving hard for the snakes, which can't easily cut the body up. The rest of the termite body was swallowed whole -- while the body was in the snake's mouth, it would start to rub the termite head against a hard surface till it dropped off. "Decapitation did not affect ingestion speed [of three seconds], and therefore, it is unlikely that decapitation assists for fast ingestion," write the authors, seemingly struggling to justify the spectacle.
There are a few alternative explanations, however. Termite heads may just be unpleasant -- and impossible -- for a blindsnakes to ingest. Undigested heads were found in the faeces of blindsnakes that did swallow them post-decapitation. "Decapitation might also be related to circumvention of chemical defences of termites because termite heads often contain toxic compounds," write the coauthors.
There are around 400 other species of blindsnake, so there could be plenty more unusual appetites waiting to be discovered. An article in Life is Short, but Snakes are Long revealed how Mizuno and Kojima discovered this particular habit completely by accident, when feeding their lab blindsnakes the termites. They only had a clue something untoward was happening when they noticed the snakes were not eating the termites head-first. After looking closer, they noticed the snakes rubbing their faces along the base of their tanks -- with the termite head sticking out. It's anecdotes like these, that lead to a published paper in the Journal of Zoology, and a secretive feeding habit revealed to the world.