Vicious dogs are often the biggest worry for postmen and women.
But in one South Norfolk village it is a collared dove which poses the biggest threat.
Known as 'Ringo' or 'Harry' to some, the bird has started harassing the local postman on St Michael's Road in Long Stratton.
And neighbours have since had to install mail boxes outside their homes to stop him from being 'attacked' while delivering letters.
'It is only in the past few weeks that he [Ringo] has made a nuisance of himself', one 73-year-old woman said.
'He is not in anyway vicious, he is just very tame and friendly. However, the postman is terrified of him.'
The dove, which is thought to be wild, only approaches people when they stray into his territory.
He then attempts to fly onto their head or shoulders, but is not aggressive.
The woman, who did not wish to be named, said: 'We volunteered to put the letter boxes outside to make life easier for the postman.
'Unfortunately, with him being a wild bird, we have no control over him'.
Joan Angier, 71, who calls the dove 'Arold, said he first came to the area in the spring of this year.
'Back then he was young and skinny,' she said. 'But he got fed by the neighbours and he became so tame.
'He's a lovely bird and we all love him around here. I just think the postman has a phobia of him.'
Meanwhile, Adrian Trowbridge, 72, said one of his first encounters with Ringo was when he flew into his living room.
'He came in the house and sat on the TV,' he said.
'He's a friendly bird, but he just has that annoying habit of sitting on your shoulder or head.
'As for the postman, I have heard of them being put off by dogs, but never a dove.'
Collared doves are a pale, pinky-brown grey colour, which a distinctive black neck collar and deep red eyes.
The RSPB said despite being a common sight in most gardens, the birds only came to the UK in the 1950s after a rapid spread across Europe and the Middle East.
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