Earlier this year, academic Dr Frances Kennett appeared in court for withholding a month's council tax after she found rats at her Oxford home.

She called for the city council to return to weekly bin collections.

The council insists that fortnightly collections have not led to an increase in rat numbers.

Andrew Ffrench joined the council's pest controllers on a typical working day to find out how to catch a rat - or a flying rat (AKA a pigeon)

Clive Williams and Tony Brind do not have far to go for their first job on Monday morning when they arrive for work at Oxford City Council's environmental health department.

Their destination is the roof of the Town Hall in St Aldate's to get rid of some pigeons which have been bothering staff.

The two men make up two thirds of the city council's pest control team - there are now only three people to combat unwanted creatures across the city.

In the late 1970s, there were four pest controllers covering Oxford. In those days, there were 400 calls a year to deal with.

Now pest controllers deal with 400 visits a month, although these are not all fresh complaints.

Mr Williams and Mr Brind are in the front line of the fight against rats, mice, wasps, pigeons and other pests.

The council does not charge for rat call-outs, and these take up most of the team's time, although council leaders say there has been no rise in the number of call-outs as a result of fortnightly collections, which began almost a year ago.

Mr Williams, 48, a father-of-three who lives near Bicester, is joined by Mr Brind, 46, from Marston, Oxford, on the Town Hall roof to lay traps for the pigeons, which have been fouling the pavements below.

Once the pigeons have been caught in the traps they will be "humanely destroyed" using a "proper dispatching tool" to break their necks.

A cull like this might take place once a year, prompted by complaints from staff, Mr Williams explained.

He added: "We have been asked to reduce the number of pigeons on the roof because they have been making the footways slippery for staff. They also block up gutters and can carry diseases which cause respiratory problems."

Once the traps have been laid for the pigeons, Mr Williams and Mr Brind climb down from the roof to take on their biggest challenge - keeping the city's rat population at bay.

Many of the calls they make are repeat visits - laying new bait for rats to ensure the rodents are killed off.

"When rats get into people's homes it's very upsetting for residents and they feel like they have got an unwanted visitor, a bit like when a burglar breaks in," said Mr Williams.

"We try to respond as quickly as we can and we use poison almost exclusively for rats, although we might set a trap occasionally if the rat is not taking the poison.

"Rats account for 75 per cent of our callouts these days but we also deal with wasps in the summer, ants, pigeons, foxes, squirrels, flies and bedbugs."

Mr Williams has been called to an address in Howard Street, East Oxford, after the Ali family found a rat running around their kitchen.

Liquiat Ali, 54, and his wife Azra have called the council before to ask pest controllers to tackle an infestation, but this was the first time a rat had actually appeared inside the house.

Mrs Ali said: "It was a small rat but it's not very nice to find one in your home - nobody likes it."

Mr Ali said the pest control team had responded fairly quickly to their complaint, and he called for a return to weekly bin collections.

"Everyone in the area wants a return to weekly collections," he added.

Statistics do not bear out claims from Dr Kennett and others that there has been an increase in the rat population as a result of the switch to fortnightly collections last November.

In 2005/6 there were 2,821 rat callouts but, according to the council, the total fell to 2,362 the following year when fortnightly collections were introduced.

Jean Fooks, the executive member for a cleaner city, said: "If someone has got a rat in their house then we come out within 24 hours but, if it is just a sighting of one rat in the garden, there could be a backlog of a couple of weeks.

"It would be nice to have one more pest control officer - we would like to have four. However, we have to make sure the service is cost-effective and there doesn't seem to be a massive backlog at present, so we will keep staffing under review.

"If Thames Water would agree to bait the sewers it would make a big difference in terms of reducing the city's rat population.

"Bristol has done a little bit of its own sewer baiting, but that needs funding."

Mr Williams added: "In the old days, when the city council baited the sewers, there were very few surface infestations and, if there was a proper sewer-baiting programme, it would make a big difference."

Don Sharples, a spokesman for Thames Water, said: "We are not legally obliged to bait the sewers.

"According to the Damage by Pests Act 1949, local authorities are obliged by law to keep their districts free of rodents.

"We no longer do blanket baiting because it is bad for the environment, but we are more than happy to work with the council to manage rodent issues.

"We have regular meetings with the council to identify problem areas."

COURT CASE: Dr Frances Kennett

In September, Dr Frances Kennett, 62, from Great Clarendon Street, Jericho, Oxford, appeared before District Judge Brian Loosley for not paying council tax. She said rats had been attracted to her home since fortnightly waste collection started last year.

Mr Loosley said there did appear to be a connection between the infestation and the fortnightly collection and Thames Water has been carrying out an investigation to see if the rats have come up through drains in the area.

Dr Kennett, who has since settled her council tax bill, said it was "astonishing" that the city council was only employing three pest control officers to cover the city.

She has set up an email account, oxfordratwatch@gmail.com for reporting rat sightings or infestations.

Found a dead rat? Bury it or burn it

Annie Skinner, of Marston Street, Oxford, asked the city council's environmental health department what to do with a dead rat in her garden in September and was told: "Bury it or burn it."

Mrs Skinner, who has lived in East Oxford since the 1960s, believes the number of rats has increased since the switch to fortnightly waste collections.

She had rats outside her home during the summer and, despite putting poison down, the creatures have now returned.

She told the Oxford Mail: "I found this dead rat in my garden and it made me feel sick.

"I didn't want to bury it for health reasons, and I didn't have any paraffin handy so I double-wrapped the rat in some plastic bags and put it in a bin in Cowley Road.

"I didn't want to put the dead rat in my own bin because there were still 12 days to go until the next collection.

"It is the pest control department's job to come out and deal with live rats, but residents now need clear advice on how to dispose of dead rats."

Mrs Skinner said she was reluctant to let her grandchildren play in her garden.

Jean Fooks, the council's executive member for a cleaner city, said: "The advice from the environmental health department is to bury rats in the garden. If residents do not have a garden they could burn it.

"If people do not want to use either of those methods, they could double-wrap the rat and place it in their wheelie bin. However, if it is a long time until collection day they can call the environmental health department and staff should come and collect it within a day or two.

"Staff cannot come and collect dead rats instantly. If people want to ring for advice they can contact environmental health on 01865 252887."