Defining what constitutes the exotic has absorbed thinkers over the centuries, pitting West against East, primitive against civilised worlds and, in Thailand, insect collectors against health officials.
A months-long craze has now come up against the law in Bangkok, with the arrest of a 28-year-old man called Pisit Pakhawan.
His crime was to be found breeding large, hissing Madagascan cockroaches which he claims were intended as fodder for snakes and crocodiles, but which collectors have been snapping up for 50 baht (HK$9) at the Chatuchak weekend market.
Why would residents of an already cockroach-infested city want to bring a new, fast-breeding strand of pest into their homes?
Part of the thrill, apparently, is the hiss these insects produce by forcibly expelling air through a pair of modified breathing pores. In the insect world, this is rare.
Male Madagascan cockroaches indulge in aggressive encounters where the more one hisses, the more likely one is to win. They ram each other with their horns or shove their abdomens against opponents, and the hisses give information about where their foe is.