Rats!

 

Rats!

If rats give you the shivers, look away now.

Top view

While gardening this morning, I came across the upper jaw of a rat. I have no idea where the rest of the skeleton is.

Underside of top jaw

Though rarely seen or heard, we know there are brown rats in our garden. When the dogs or cats become particularly interested in one area we suspect they have tracked a rat and when that area is investigated, we find traces – a narrow, well-worn track, a hollow leading to a hole and into a tunnel.

Close-up of molars

We have seen rats appear from underneath the waterfall and swim across the pond. We have watched them climbing a metal pole to reach a bird feeder. These intelligent, opportunistic rodents are fascinating to observe, beautiful, sleek, agile, but we know they must be controlled, sadly. As much as it goes against the grain to kill them, it has to be done.

Close-up of incisors, which continue to grow throughout a rat's life

 Though they look fit and healthy, there is no way of knowing whether or not they are carrying Weil’s disease (leptospirosis) which is spread in rats’ urine, or other diseases, such as salmonella and toxoplasmosis. The bacteria infect people through cuts and grazes. Rats have no control over their bladders and urinate as they move. However, Weil’s disease is rare in the UK.

 Notwithstanding that, rats can cause a lot of damage – to electric cables, wooden outbuildings, crops, not to mention the nerves of susceptible humans.

The brown rat (Rattus norvegicus) originated in Asia, appearing in the UK in the 1700s. It travelled on ships throughout the world and is found on every continent, apart from Antarctica. It is extremely adaptable and will make its home anywhere there is shelter and food.

Rats are truly omnivorous and eat a huge variety of foods, from birds to underwater molluscs, from cereal crops to insects. The reason for their great success lies in their adaptability and phenomenal ability to breed rapidly. They reproduce all year round, the females starting at three to four months of age and bearing litters of around six, though one litter of 22 has been recorded. A female may become pregnant immediately after giving birth and can raise an average of five litters a year. In cases of rarity of food, a pregnancy may be extended by two weeks from the usual 21 to 24 days.

Rats are not territorial but live in colonies in burrows they dig. They favour compost heaps, because they are easy to burrow into. The compost they have nested in can be used in the garden but it’s probably wise not to use it for growing fruit and vegetables that may be eaten raw, like celery or cucumbers.

The world is not overrun by rats because they make a tasty morsel for many mammals and birds. Owls, foxes, stoats, cats, even herons, will deplete the population. Most rats will not live beyond their first year in the wild.

Pet rats are a different case altogether. We have kept mice and gerbils and hamsters, but never graduated to rats. It seemed wrong to keep a relatively large mammal in a cage – and far too tantalising for our cats and dogs.