What is a bee? ‘A well-known insect,’ says the Oxford English Dictionary, passing the buck rather. Similarly, an ash is a ‘well-known forest tree’, an ass is ‘a well-known quadruped of the horse kind’ and asparagus is ‘a well-known delicacy of the table’ — not caviar, which is ‘eaten as a relish’.
Being well-known is an unreliable category. One man’s Kim Kardashian is another man’s Lyndal Roper. I remember encountering caracoles on a Spanish menu and being told that by the waiter that it was a kind of animal with horns. It took me a long time to get from that to ‘snails’. When the OED says that an aucuba is ‘a well-known hardy evergreen’, I am none the wiser till my husband chips in with: ‘That horrible variegated laurel.’
A clue sometimes deployed by the OED is the ‘voice’. Whose voice is a neigh? Yes, the ‘solid-hoofed perissodactyl quadruped’. What has ‘a barking, howling, or whining voice’? Why, ‘a domesticated carnivorous mammal’ of course, to be distinguished from ‘a well-known carnivorous quadruped’ which may be ‘kept to destroy mice’. Mice? ‘In Europe,’ says the OED chattily, ‘mice are perceived as differing from rats mainly in their consistently smaller size; elsewhere the size difference can be less clear cut and the two terms are used interchangeably.’
Another difficulty for the OED in pinning down well-known objects is that it (rightly) takes an historical view. So what is a fly? ‘Any winged insect; as the bee, gnat, locust, moth’. ‘Waiter,’ you might once have said, when a locust or moth was striking out for the closest shore, ‘there’s a fly in my soup.’ And with your soup, would you ask for ‘a well-known article of food’ and expect bread?
What’s the difference between a sheep and a goat? One is ‘noted for its hardy, lively and wanton nature, and its strong odour’ and the other’s ‘intestines are used for the strings of musical instruments’. Other members of the animal kingdom seem almost to have lost their specific names. A cock, for example, and a hen are the male and female of what? The best the dictionary comes up with is ‘barn-door fowl’. First, then, find your barn.