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          | Colney Nature Watch |  
          | A series of articles on the wild life in London Colney |  
          | Rats |  
          |  Recently I saw some beautiful rats. 
        They were clean and their fur shiny. Their eyes were bright and alert. 
        They looked happy and intelligent. They were living in rats heaven! 
        The garden owner was a keen ornithologist. He put out grains and nuts 
        for the birds to eat. The excess food fell to the ground, and the rats 
        were only too keen to eat it. For most rats - life is hard. But these 
        rats had a steady food supply in a wooded area which was only visited 
        by people who valued wild life. These rats lived in a colony of females, 
        ruled over by a dominant male, who would see off any other rats who came 
        into the area. You can often hear rats squeaking to each other, but they 
        usually communicate by ultra-sound - which we cannot hear.
 If you see a rat, it is most likely to be a brown rat (rattus norvegicus), 
        rather than the extremely rare black rat. Brown rats can be a wide variety 
        of colours, and were first seen in Britain in 1728. Because they thrive 
        near places people work and live, they largely displaced the native black 
        rat, in the same way that the introduced grey squirrel has replaced the 
        native red squirrel.
 People who keep rats as pets find them friendly, affectionate and intelligent. 
        In Angola and Mozambique, rats are used to sniff out land mines. They 
        can smell the TNT in them, and because they are light, do not set the 
        mine off. Their owner can defuse the mine and destroy it, after rewarding 
        the rat. Large areas of land in both countries have been rendered cultivable 
        thanks to these useful rats. Yet here, most people dislike rats - and 
        with reason.
 Rats will eat any food that people like. The problem is,rats render the 
        food they dont take inedible. They defecate everywhere, and they 
        leave their urine all over the place. Outside they leave urine trail, 
        so other rats can follow them. - This is a mixed blessing, as many carnivorous 
        birds see dried rats urine, and know where to lurk if they want 
        to catch them. Rats urine carries a variety of diseases, and because 
        there are many rats living near our river, we recommend that people do 
        not bathe in the river.
 Where food and shelter are good, a pair of rats could produce five litters 
        a year. Each rat is sexually mature after three months, and a litter can 
        contain a dozen. Youll wonder why Britain isnt meters deep 
        in rats!
 In the wild, rats face many enemies. Owls, hawks, kites and snakes eat 
        rats. So do foxes and badgers. Most rats die young because there is insufficient 
        food around, others from illnesses, in accidents, or in fights to establish 
        themselves in already occupied territory. A healthy dog who has already 
        killed a few rats will have no difficulty killing more. However, cats 
        are not a lot larger than rats, and in a confrontation could end up receiving 
        nasty bites that could take time to heal.
 A few years back, I had rats in my composter. I phoned the council, who 
        sent a personable young man round to discuss the problem. He put a tray 
        of cereal in the composter, which the rats ate. When he came next time, 
        he put more cereal in the composter - but this time laced with anticoagulant 
        drug, the rat would eat it and subsequently die from internal bleeding. 
        Next time the rat catcher came, he was able to show me the carcase of 
        a rat he found in my composter.
 If you ask the cou ncil to send a rat catcher today, they will not be 
        so willing. They will ask for evidence that you have a rat problem. and 
        then tell you to stop putting kitchen waste in the composter, only garden 
        rubbish. After a while, the rat will realise hes not on a meal ticket 
        for life, and go elsewhere. The anticoagulant drugs which were once so 
        effective at killing rats do not work so well today, as all the rats which 
        were once susceptible to the poison have died without issue, and the rats 
        which were more resistant have mated with other resistant rats to create 
        a new population that is immune to the traditional poisons. If a rat dies 
        from poison, and a dog or cat finds it, they will happily eat it, making 
        themselves ill - or worse.
 So if you find rats living in your compost heap youve two choices, 
        either you poison the rat, and risk hurting other animals. or you put 
        kitchen waste elsewhere, and make sure there is no food lying around which 
        rats particularly like. Its up to you!
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