The t0ss of a coin

[seal!]

Heads is called heads for obvious reasons, but why tails?

[Tat]

got a ten pence piece? have a look at it...

[bernardo]

In the old days they used to glue a mouse's tail on to the reverse side of each coin, as an aid to blind people who wanted to know which side was heads and which was tails. This practice fell into disuse - partly because of the animal rights issue (millions of disgruntled tail-less mice) but mainly because it eventually occurred to people that blind people did not actually need to know which side of a coin was which in order to use them as currency. The practice died out in the early 19th century, but the terminology remains.