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There are approximately
2000 species of rodents, but only 3 kinds of rodents will be discussed
in this particular field, • Rattus norvegicus (Brown rat)
• Rattus rattus (Black rat) • Mus musculus (House
mouse)
All are described as commensal rodents “sharing one’s
table”.
Rattus norvegicus
- (greyish brown, reddish
brown)
Slightly larger animal than the roof rat. The nose is blunt, the ears
are small, the tail is scaly and shorter than the head and body combined.
They burrow to make nests under structures,beneath concrete slabs
and along stream banks.
Rattus rattus
When necessary, roof rats will travel considerable distances for food.
They can often be seen at night running along overhead utility lines.
Roof rats have a strong tendency to avoid new objects in their environment
and this can influence control efforts. These rats may take several
days before they will approach a bait station.
Roof rats have an excellent sense of balance. They use their tails
for balance while traveling along drinker pipes and are very agile
climbers.
When distinguishing the Norway rat from the Roof rat, pull the tail
back over the body. The tail of the Roof rat will reach the nose.
The tail of the Norway rat will not reach beyond the ears.
Rats in general
Rates see poorly, relying more on smell,taste, touch and hearing.
They are considered to be colourblind, responding only to the degree
of lightness and darkness of colour. The average life of rats in a
population is obout six months,and rats rarely live much over two
years.
NEOPHOBIA - new object fear.
Placing an unfamiliar object (such as a box) in the path of a rat
effectively prevents it using that path, and is now classed as a obstacle.
The rat will take several days before it will venture into the box
and take the poison. Allow for one week before relocating the box
if no feeding was found.
Rodent move for four main reasons:
a. food b. water c. shelter d. breeding partners these types of movement
are termed “voluntary”. Movement by means of transportation
in goods and by vehicles is “involuntary”. Female rats
can move up to 340 m in one night and males 660 m. Rats reach a peak
of activity ± 2-3 hours after the onset of darkness,and a smaller
peak an hour or two before sunrise.
Rats do prefer a clean meal, keep this in mind next time you
open your bait station and find a frog, spider and half a rubbish
dump around the poison. Keep your poison clean and the bait station
clean. Contaminated poison is a problem that leads to poor rodent
control. For example:
a. the person applying the poison did not wash his or her hands and
diesel has tainted the product
b. the rat has urinated on the poison (to keep other rats away)
c. too dirty (dust, feathers)
Rat runs: A rat run is usually from a food or water source to the
nest. If looking outdoors a well defined run will be narrow and clear
of grass,indoors will take place against a wall overhanging pipes
or cables and free of dust and cobwebs.
Grease marks are generated by several rats entering a small entrance,
this is made by the oily layer mixed with dirt on the rats fur. (look
like a candle burn mark)
When looking at an area and not knowing how much poison to
place one should look for the following,
a. number of droppings
b. grease marks (entry and exit points)
c. foot prints (look for dust on pipes and beams, if there is no dust
on one, but dust on another, it is a rat runway)
d. odour
e. damage (rats need to chew all the time to wear down their teeth
e.g.: electric wires, fittings, drinker pipes, timber lead pipes) |
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