Telephone wiring

Can you explain the reason behind this ?

Hello Skelley

The conduit needs to be metal, if it is plastic, those mice are going to chew through conduit and all.

Mice, like rats, beavers and others, have continuously growing incisor teeth.

If the teeth are not worn away on the ends, the teeth can grow so long they curve back and grow through the skull then the brain of the unfortunate rodent.

The best way is t0o ensure your house is properly rat and mouse proof, not always easy, because they can enter while quite small.

For a mouse, the human habitation is the equivalent of the Realtor's statement: "Handy to bus and shops".

PVC and Polythene plastics are enticing to rodents.

Kind Regards....

Hi Sparky,

I concur with your explanation of why rodents chew electric cable, but there doesn't seem to be much solid proof on the web. Apart from occasionally getting fried, this doesn't seem to do them any harm. Do you reckon the electric field excites them ? I'm serious ! Sharks reportedly detect electric fields, and who hasn't got a perversly enjoyable feeling when touching a 9v battery to the tongue*. Perhaps somebody who has pet mice/rats/squirrels can investigate by giving them some (non-live) cable to play with. I doubt they do it for nesting material, since nests full of plastic would be reported.

* There is much web-debate about what electricity 'tastes' like. Sulzer and Volta first reported this back in the 1700'sMaybe the 5 supposed tastes need adding to, although I'd say it was just nerve stimulation. The supposed 'tongue taste-map' is reckoned to be bunkum.

Kris, I was told when I had a mice 'invasion' some years back, that the blighters chew the pvc cable because it has the remains of human sweat or grease on it and it does attract a hungry rodent...

Don't know whether it is true, but the pest exterminator knew his job!

John.

That sounds plausible, but they chew stuff that has been around for years. Also, a lot of chewed stuff must be un-contaminated and 'fresh off the reel'. Maybe they just enjoy chewing, the same as a dog with a plastic toy or a baby with a 'passifier'* ? Gordon Brown does something odd with his tongue all the time, so maybe it's a self-comforting type thing. Wiring regs should incorporate something like a sacrificial anode, in this situation a lard-soaked armoured cable.

* I should have used a comma. Poor baby.

I would agree with you Kris. There were two cases what I was experienced in my life:

1) When I was a boy my late grandparents home was time to time invaded by rodents. Their house had old design where not only telephone wires were placed outside the walls but power supply one being protected in noway. Rodents gnawed everything what its could find, but I don't recollect its touched any wires ever. And my grandparents didn't care about wires.

2) Eight years ago or so I was invited as consultant for fixing problems with field located truck scales. I was so wonder when I'd found that malfunction of scales had been caused by bitten through cables (both control and power one) placed in metal armed conduit. There had been found even one dead rodent near cutting off cable along ditch.

I am not biologist but I would suppose that rodents can be "educated" by means of their genome coding mechanism. Therefore urban rodents are believed shun to treat any electric wires but field ones can do that silly things as "under graduated" .

I doubt that the genome changes, but urban critters probably learn new tricks. Our household rubbish was collected in plastic sacks at one time, but now we have big 'wheelie-bins'. The reason for change is recycling, but it has other advantages such as stopping Seagulls from having a free picnic. Foxes will still have a go though, and cubs probably learn bin-tipping techniques from their parents. I still haven't discovered if rodents chew non-live wire that is lying around, but I suspect they do.

9 VOLTS [from a small battery]tastes sour to me, the degree of sour lets me know the amount of charge remaining.

If you're going to spring for conduit, might as well throw in some cat5 too, you never know where you might need a network connection! Wireless sucks.

It's all well and good to insist on all your cables being in conduit, until it comes time to pay the extra cost for an additional three hours work and twenty meters (65 feet) conduit. And what about all of the electrical TPS? Seriously, just through some rat poison in your roof and avoid the whole situation to begin with.

The mice won't be around to see your face after they bite into a 50V line anyway. (90V if they're unlucky enough to have the phone ring while they're dining.)

The mice won't be around to see your face after they bite into a 50V line anyway. (90V if they're unlucky enough to have the phone ring while they're dining.)

I know this is being pickey but a telephone serviceman once told me that if you check the ring with a scope or a peak to peak voltmeter it is actually 120 volts. This was in Florida. It could vary elsewhere.

You want a bet?

The mice invasion of 1998 in my house, began with me picking up the phone and finding it dead.... I followed the cord and sure enough it was nibbled in several places right through the copper wire...

So those mean mice were quite happy nibbling through whatever voltage the telecoms people put out!!

John

Personal experience indicates they go through 1/2" 'Alkathene' cold water supply pipe too.........

Hello Skelley

<"Rats cause serious damage to property. They can chew through concrete, metal and wood, and scratch through stone.">

Quote above from: http://www.yorkshirepost.co.uk/country-view/The-rat-pack--meet.3832857.jp

Kind Regards....

I once installed some comms cables in trunking embedded in a wall in the Seychelles. Next morning the circuits were dead with a section missing where it had been gnawed through. The rats literally used the trunking as a rat run, I assume the cables got in the way and were chewed through. I have also seen this happen with mains feeders in India only the rats did not survive that incident. The solution was complete sealing of the trunking as well as trapping and poison.

I understand that they (at least in the olden days before OSH) put some sort of deadly poison (like Deildrin) in underground telegraph cables to kill off the termites which also seemed to like both paper and PVC.

It sort of stopped me using such wires for prototypes when I found that out. It especially stopped me from using my teeth to strip the insulation off!!!!