Jay Foxing Posted March 12, 2008 Report Share Posted March 12, 2008 The Brown Rat (Rattus Norvegicus). This early 18th century immigrant has managed to adapt to every environment in the British Isles, a true survival expert. Also known as the Norway, Sewer or common rat, it has concurred our lands with ease. Anywhere you have a food source that is relatively undisturbed you will find this disease carrying problem. Measuring 20-25cm in length and with its tail adding another 15-20 cm it’s easy to distinguish from a little mouse. Generally brown coloured fur (this may vary from rat to rat) and its pink thick tapering scaly tail, small ears covered in fine hairs and almost black beady eyes. A fully grown rat can weigh in at 150-500g, but average around 300g. Dropping are cylindrical and about 15-20mm long, often flat at one end and pointed at the other. Moist when fresh but drying within hours, you can locate recently used sites easily. Footprints and tail marks can sometimes be found in soft mud or dusty sites, giving away a rats regular visiting area. Found in buildings of all types, refuse tips, farms, crops and field margins, river banks gardens and park land the rat burrows into its chosen habitat spreading disease and causing considerable damage. Burrows are around 8cm in and about 2ft deep into banks and earth, also living within man made structures such as buildings, tyre heaps, pallet stacks and mounds of rubbish. Living as a complex social unit, dominance hierarchy determining the social status of each individual. Large infestations often consist of a number of smaller social groups with their own territories within a large area. These territories are defended fiercely with intruders being attacked. Rats will travel up to a km for food but the average range of a rat is 10-500 m2, preferring to live as close to an abundant food source as possible. Moving along well defined runs of about 5-8 cm wide can clearly be seen as continuous paths through vegetation and alongside walls. Mainly nocturnal, active the most just after dusk and just before dawn. Though if left undisturbed by predators during the day and predation risks are greater at night they will become more active during daylight hours. This is also true if there is a large pressure on available resources, this often happens with large rat population. Rats need food, water and shelter to live. In large infestations, rats will run around the clock to over come this increasing pressure. As an omnivorous mammal a rat will eat a varying diet, preferring cereals and proteins. Will also eat fruit and vegetable remains, predate on slugs and insects. They have been know and are very capable of taking frogs and small birds, eggs are highly prized. Consuming 25-35g of food each day, a large population can have a devastating effect on certain food stores. Rats carry their food to safety, preferring to dine in under cover. Baited areas you will often see poison blocks of packets protruding from burrows where a rat has tried to take its supper to ground. Its also worth mentioning that the rat can become cannibalistic under certain conditions, though this is uncommon. The Brown rat can live up to 3 years of age, but uncommon for it to last beyond 2. With a female reaching sexual maturity at 8-12 weeks and a gestation period of 21 days, populations can rise very quickly. Litter sizes of 7-9 and young being weaned after 3 weeks, I will let you do the math. Female rats normally having 5 litters a year with breeding peaks in spring and autumn, but if conditions are mild or when living indoors rats will breed all year round. The rat has many predators to avoid apart from man. Dogs, cats, owls, stoats, weasels, polecats, foxes and occasionally badgers will eat rats. In urban areas cats are the rats main predator, though a large adult rat is a fiercely difficult prey to tackle for any predator so more often it’s the young that is preyed upon. Rats have razor sharp teeth that never stop growing, they have to gnaw on things to keep them in check. They can chew through wood, wire and concrete so a bite from an adult can cause much pain and damage. Often inflicting multiple bites to its attacker before its overcome, the rat is surprisingly fast with lightning reactions. Rats carry a number of diseases that can be potentially fatal to humans as well as animals, Leptospirosis (also known as Weil’s disease or rat catchers’ yellows), Toxoplasmosis and Salmonella are among some of the worst. Couple that with the considerable structural damage that a rat can cause with its gnawing and burrowing, you have to admit that complete eradication would not be a bad thing. Thanks for reading, Jay. Quote Link to comment Share on other sites More sharing options...
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