It's the urban legend that sends a shudder down all of our spines, that when in a city we are never more than six feet from a rat. While the truth of that may well be doubtful, though, one thing is for certain – rats are on the rise.
The average adult rat in Northern Ireland spans about 12 to 15 inches – not including the tail.
There have been reports of giant rats found all over England, in Dublin and in Sweden.
The bad news for Northern Ireland is that they're certainly getting bigger and heavier, although we may not have found any giant rats yet.
Increasing levels of food waste, fly tipping and plenty of cosy holes to curl up in now make cities the perfect place for a rat to settle down.
Imagine Belfast city centre after a Saturday night, littered with chip papers and leftover burgers. This is the perfect breeding ground for furry friends.
The creatures can cause untold damage, from ruining buildings by damaging the structure to gnawing through electrical wires, sometimes leading to fires.
In retail premises they have been known to destroy thousands of pounds worth of stock by chewing through boxes. And that's before you consider the diseases they carry, from the potentially fatal Weil's Disease to salmonella, tuberculosis and foot and mouth disease.
Lately, however, people in the UK have been reporting the discovery of giant rats.
In Liverpool a two-foot long rat was caught by pest controllers.
In Dublin, meanwhile, a 24-inch rat was discovered in another family home. These super rats are certainly on the rise, it seems.
Spare a thought, then, for those who risk the bites, scrapes and even worse to take on the pests.
We spoke to three pest controllers about how they deal with the things that scuttle in the night.
'Recently, I found one the size of a carrier bag'
Earl D'Hulst (56) is the pest control manager for Belfast City Council. He is married to Donna and they have four grown-up children. He says:
My career began at Rentokil 29 years ago and now I've been in my current post at Belfast City Council for the last 12 years.
The average rat from the tip of his nose to the tip of his tail is about half a metre long – 24 cms long in the body.
I did find a really big rat about five months ago – he was about the size of one of those large bag-for-life carrier bags. They really can vary in size, so it's not that surprising to find a lot of big ones.
It's rare that we actually find a live rat, as most of the time we find dead ones. We use poisons most of the time, because traps have been used for so long that rats are almost genetically better programmed to understand how they work. They know how to get the bait without setting off the trap, and once the trap is down, it can't be used again until it's reset.
I love my job. Most people think that as council workers, we're going to enforce some sort of law or impose a fine. The service we have provided here for the last six years has been provided free for domestic ratepayers. The elected members of the council are showing their concern for the health of the citizens who live here.
My wife and children don't mind what I do. I've been doing this for nearly 30 years. I can remember years ago working in the private sector, working on farms dealing with pests. I have to strip in the garage when I get home – my wife would put the clothes straight in the washing machine and I would step straight in the bath.
One time, I brought fleas home with me – they were in a school which had been built six weeks earlier. A bird's nest had been built into the wall and I got fleas in my hair. Thankfully, they drowned when I got in the bath. That's the only time I've brought any of my work home with me.
The only think I'm squeamish about is American cockroaches – they're the ones that are about two inches long. We're seeing those over here more often and they're not very pleasant. People are bringing them back from Europe in their cars – I know someone who opened their car boot and a roach fell straight on to them, as it had stowed away.
When people ask us to come out, by the time we've finished they think we're the greatest thing since sliced bread. There are six officers who go out to the domestic ratepayers and three officers who spend their time in the sewers on behalf of Northern Ireland Water.
We've done the first actual monitoring programme in the sewers to find out how bad the problem is down there. In Belfast, about 77% of sewers are infested with rats and mice. You need certain conditions to have giant rats: heat, protection and food. Remove one of those three and the rodents won't be there anymore."
'There's a lot of food for them, especially in the city'
Rex Smith-Holley (63) lives in Belfast with his wife Julie, and they have three grown-up sons, Dean, Barry and Tony. He works as a pest control operator for the Concept Group. He says:
I've been in pest control in Belfast for six years now and I did it for 10 years before in New Zealand, where I'm from.
I haven't seen any giant rats, but they can get pretty big. The biggest ones I see are about six inches in size but that varies -- you don't always catch the adults. I found one the other day that must have been an old male. He was about eight inches long.
They are getting heavy, though, more so than they have been. There's a lot more food out there for them, particularly around Belfast. A lot of it is in bins that have holes in the bottom of them, or they climb up and go in the top. If you walk down an alleyway here at night you can hear rats in the bins or even see them. I've driven into town and seen them running down the gullies.
Most of the time we get called out by businesses but we do get called out to private houses too.
One call-out was for two houses next to each other that both had rats. I have to survey them, find out how bad it is and how the rats are getting in, then I get rid of them and block the holes up. It's important that people are happy that they're definitely all gone.
People over here have a phobia about rats and mice -- I've even seen grown men petrified of mice -- but I think it's because they're only really starting to come into houses.
We've made a habitat for them. We give them water, a place to live and food. Lots of houses aren't rodent-proof either.
There's nothing I'm squeamish about -- in New Zealand a lot of my jobs were with cockroaches, ants, flies, bed bugs and the like.
I used a lot of insecticide too on poisonous spiders.
I've never seen poisonous spiders here but I have noticed cockroaches coming into the country, both of the German and American species.
The German kind is the worst because they spread diseases. People tend to squash cockroaches but if the female is in danger then she drops her egg sac so the little ones will hatch anyway.
If you do find a cockroach, catch it and if you must kill it, do so in a container and throw the whole thing out."
We are seeing more of them in people's houses'
Steve McCart (55) is the owner of Pest Force Northern Ireland. He lives in Doagh with his wife, Hilda, and they have one grown-up son, Ian. He says:
We haven't seen any giant rats, but we are starting see rat populations get bigger. They're like anything; you get large ones and small ones, but the adult population is getting larger. You would see a rat now that would be 12 inches long in the body – that's one or two inches longer than normal and doesn't include the tail.
I have seen, though not caught, extremely large rats, but those are the exception. The biggest one would have been about 15 inches, but that was a bit of a freak occurrence.
The common brown rats are the ones you normally get in Northern Ireland. Black rats are quite rare here and they're the ones who are able to climb things.
People throw away their burgers and takeaways, which are a very high-protein food. Rats are feeding on them from an early age and that strengthens their skeletons. It's the same as for humans – high-quality food will make them stronger.
Bins are becoming a problem too. They're now lifted every two weeks and we're encouraged to recycle food waste in caddies. As the food rots it begins to smell, so people put the caddies outside their back door and that attracts rats. We're seeing more and more rats in people's houses instead of just the bag yards nowadays. We see both alive and dead rats, as we specialise in trapping them instead of using poison. The difficulty is, if you kill a rat with poison and you can't actually reach it after it dies, it will start to decompose, and the smell of rotting flesh will be in your house for at least six weeks. We only use poison as a last resort, though.
I started the business 11 years ago because I've always liked animals and people always asked me to take care of one problem or another. I love the job; I'm out and about over the place working with all different kinds of people. The most unusual things I've come across are snakes – they've appeared in a house after they've escaped from somewhere else.
We've had houses where people thought they had mice and it turned out to be large numbers of rats. People leave crusts of bread out for birds, which encourages rats and mice and even squirrels, which are becoming a problem. The best thing to do is deal with problems in your house quickly. A hole in the skirting board left alone for a couple of months is an open invitation.
My wife is absolutely fine with what I do – as long as I don't bring anything home. It's never happened to me, but I have heard of other guys bringing bugs home. Fleas, bed bugs or even cockroaches. You have to be careful you don't bring the eggs home on your boots. You wear masks, disposable overalls and even rinse down your boots."
Keeping unwanted visitors out
* Make sure all holes and gaps around your house are blocked as soon as they appear, even holes that are higher up, as rats can be excellent climbers
* Ensure that all waste food is secured in bins or caddies. Make sure that all food is stored securely and that taps don't drip as they can be a source of water for rats
* Avoid feeding animals – particularly dogs – outside. Rats are partial to dog food