Responding to the experiments of cockroach-controlling neurologists Backyard Brains – featured previously on the Dish – Brandom Keim looks at the evidence for insect sentience:
Before dismissing bug consciousness out of hand — their brains are so tiny! And, they’re bugs! — it’s worth recalling that one of the first scientists to seriously consider the notion was Charles Darwin, who spent most of his adult life, even as he completed The Descent of Man (1871) and On the Origin of Species (1859), thinking about earthworms. … Among the surprising — to me, anyway — facts detailed by [ethologist Mathieu] Lihoreau, [and researchers James] Costa and [Colette] Rivault about Blattella germanica (the German, or small cockroach) and Periplaneta Americana (the American, or large cockroach), found in kitchens and sewers worldwide, is their rich social lives:
one can think of them as living in herds. Groups decide collectively on where to feed and shelter, and there’s evidence of sophisticated communication, via chemical signals rather than dances. When kept in isolation, individual roaches develop behavioural disorders; they possess rich spatial memories, which they use to navigate; and they might even recognise group members on an individual basis. Few researchers have studied their cognition, says Lihoreau, but cockroaches likely possess ‘comparable faculties of associative learning, memory and communication’ to honeybees.
As to whether cockroaches possess a self, in the pages of Cockroaches: Ecology, Behavior, and Natural History (2007), co-written by William J Bell, Louis M Roth and Christine A Nalepa, I happened upon a reference to Archy, a popular early-20th-century cartoon cockroach who said: ‘Expression is the need of my soul.’ Archy’s inclusion was intended in fun, but there was a grain of truth. Cockroaches could very well possess a sense of self, and one that’s perhaps not entirely alien to our own.
The Dish 