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.