There are two main species of rat that can be found in Britain. They are the Brown Rat, aka the Common Rat and the Black Rat, also known as the Roof Rat.
The brown rat is the larger of the two rats, usually weighing over half a kilo and measuring about 23cm. The Brown Rat is a brownish red colour, a hefty individual with a thick body and a blunt nose. Its ears are smaller and rounder than the Black Rat, and it has a shorter tail.
The Black Rat weighs half as much and is much shorter than the brown. It is a dark grey in colour rather than black and has a thinner body and pointy nose. Although all rodents climb well, black rats are truly excellent at scaling walls thanks to extra pads and digits on their paws.
All rats are very suspicious of any change in their surroundings, so any control measures should take this into account. To catch a rat you need patience. The appearance of rat bait boxes or traps, or a change in their territory will make rats very wary.
Rats in the Home
If you discover you have a rat or rats in your home then one of the first things to do is try and find their point of entry as without doing this the problem will recur.
Rats are dependant on food sources and in particular a supply of water so ensure none of these are available in the home.
Check around the exterior of your house looking for missing air bricks or holes that may have been created when installing pipework or drainage. Rats are very proficient climbers so look upwards for any entry possibilities, including under the eaves. A rat can enter through a hole of 5cm’s.
Internally check for access points under baths, sinks and kitchen units anywhere that someone may have created a hole or gap, around pipework is the most common.
Seal up any holes that you find in brickwork you can use mortar or a special rodent proof product like Mousestop which is easy to use around pipework. Expanding foam or a filler can be reinforced with steel wool or wire mesh to deter them chewing through.
Holes in wooden flooring should be repaired with new boards or patches, if you suspect rats are active under the floor it would be worthwhile inspecting underneath for any signs of entry.
Check the attic or roof space for any signs of activity, droppings or gnawing marks. Hopefully your house is detached otherwise you will need to consult with your neighbours.
Once you have determined that rats are your problem and you have done your best to prevent further access you need to decide which will be the best control method to employ.
Rat Poison is the most effective method but can lead to odour problems depending on where they die. If you do go down the poison route then you must use a rat bait station to contain the poison unless you can be certain that there is no possibility of secondary poisoning of pets are children.
The other method is using break back type rat traps. This also isn’t straight forward as rats are wily creatures. The secret is the siting of the trap and the bait you choose. There is a vast array of tasty morsels you can try like peanut butter, bacon, chocolate and nuts. Sometimes a piece of fruit can do the trick.
Rats in the Roof
Rats can usually gain access to your roof without do much difficulty. They are very good climbers and will scale something like a foul air drainage pipe which usually protrudes above your gutter and then through any gaps they find in the eaves. If you house is covered in a rough pebbledash render this also aids them.
If the rats are in the roof area only then poison is probably the best option, as you can hopefully access any bodies to remove them. In the attic you can get away without using a rat bait box, but it is still a good idea to fix the poison so you can monitor the feeding. A nail through a poison sachet or a poison block into a piece of wood or roof joist will do the trick.
Rats need to feed from the poison regularly so ensure you check all your bait points and top up regularly. Three bait points will probably be sufficient in the average attic.
Assuming they are feeding from the poison, after a week check around the attic for any bodies and dispose of by burying or bagged with your household waste.
Keep baiting until there is no sign of bait being taken. Give it another week and remove any old poison. It can be disposed of wrapped in your household waste or retained for later use.
Rats in the Garden
Having rats in the garden is quite common and in most cases caused by feeding birds or any other wild creatures. The easy source of food is irresistible to rats. Compost heaps also attract rats so take care what you throw on them. The other cause of rats in your garden can be through a damaged drainage system. If you suspect this to be the case then further investigation will be required.
The best outdoor control method is rat bait blocks in a rat bait station, as the bait can be securely held on the metal rods inside the box. This will help ensure you get no secondary poisoning. The last thing you want to do is poison a family pet or hedgehog.
Look around your. garden agains fences and try to identify the rat run or any burrows that have appeared. Place the bait boxes adjacent to the runs.
Sheds are also places that attract rats if they are venturing inside use a bait box here. You can place poison sachets under the shed if your are sure they wouldn’t be accessible to non-target species.
Most rat bait boxes will also accept a rat trap so if you want to try the trapping method this allows you to do this whilst protecting pets and other wildlife.
Check the baiting points regularly and top up as required. Once you are happy you have controlled the problem remove all bait points and poison and retain for possible use later.