OMG SNAP !!!
I had excatly the same thing i promise its not a wind up lol
Ela will remember me saying about it an another board last year
My postman knocked on my door one morning with blood dripping from his hand and said
"your dog has just bit me "
I told him i didnt have a dog and he said well something has just ripped my hand open when i put the letter through your box !!
He wasnt very happy and i got something to clean his hand with and explained i only had cats lol
To cut a look story short, i had to get a sign put on my letter box which reads "Beware of the cats #