If you really want to keep them out, which I personally would prefer to do, more for the danger of diseases like leptospirosis, etc., which your dog(s) as well as you can get, then using traps, or sprinkling ground cayenne pepper in front of the holes or dried mint leaves, might work. I know the cayenne will keep squirrels out of my bird feeders - I mix it with the seed in the storage container. And I have been told, and tried in my brother's tackroom (until he got a cat), that essential oil of peppermint mixed with water and sprayed several times a week around the area will keep mice out. The drawback is you have to keep doing it. But, if you are going out to your compost pile several times a week with scraps anyway, then using something each time to keep the beasties away won't be a problem. You can also try using rat traps, if you can think of a bait that won't also attract dogs - I would toss the carcasses off into the field, using washable or disposable gloves - and let their "friends" take care of them. If, that is, your dogs don't also patrol the field, when I would wrap the carcasses in newspaper or a plastic bag and toss them in the garbage.

This forum is for pictures; you may want to post on the compost discussions forum to get replies. Good Luck!

I think that the final heating to the point of ignition comes not from bacterial activity but from the fact that anytime you put fuel molecules and oxygen molecules together a few of them will combine chemically and release heat. Whether you consider this burning goes back to the definition of fire. I don't know the formal definition but my own personal definition is that fire is a self perpetuating exothermic reaction that builds up in temperature and is limited by the availability of either fuel or oxygen. By the time this happens stuff is glowing red hot (flames). We are used to viewing objects as conglomerates of unbelievably large numbers of molecules. There is the posibility that one of the atoms that make up your left little toe is at this moment on the far side of mars but you don't really notice that it is missing. The probability that all of your toes atoms should be AWOL all at the same time is infinitely remote, therefore you can be excused for believing that your toe can't be anywhere that you didn't put it, even though parts of it literally are somewhere else sometimes. Similarly, temperature of an object is the average of the temperature of all the atoms that make it up. Some of your toe atoms are at absolute zero. Some are at 10,000 degrees. The average is 98.6 degrees. Now, if you create a nice warm stable environment with just the right ratio of fuel to air, some fuel/air couples will "get it on". They give off heat. If the insulation is good, the temperature rises. If the insulation were really really good, all that is necessary is time for the temperature to slowly rise, even without the effect of increased temperature causing an increased rate of chemical reactions. What I am saying so far is that the chemical reactions that occur in fire can happen at almost any temperature but we don't call it fire until we get the increasing chain reaction where more chemical reaction causes more heat causes more chemical reaction, etc, until the only thing holding things back is a shortage of one of the reactants. Almost always stuff is so hot by then that it is glowing red hot (fire). I believe that haystacks can start on fire not so much because of 170 degree bacterial activity being the ignition point but because a large enough composting haystack creates a wide enough range of microclimates that one of them will have just the right combination of fuel (methane, cellulose, hydrogen, ethanol, etc) and oxygen, combined with really good insulation and a good 170 degree head start. I read an interesting thread on the flamability of sprayed on urethane insulation. If you take a chunk of it and put a flame to it it will smoulder and go out but there have been some horrific fires in large metal storage buildings coated with the stuff inside precisely because it is such a good insulator. The heat can't get out. Eventually, by which I mean within a minute or two, temperatures shoot up to the point where anything capable of burning would burn, and so the insulation does. So would wet compost only compost has a high thermal mass and a more modest R-value so it takes longer and the ideal conditions are met less frequently. The point is to embrace modern physics and the idea that for atoms you can't nail down such mundane physical properties as where they are and how hot they are, only the probabilities of such. These probabilities often have peaks that might lead you to draw sweeping conclusions such as that your nostril hairs couldn't be on fire, while in reality every so often a hair molecule does in fact combine with oxygen and give off heat. It couldn't be otherwise. In a large compost pile, which is almost infinitely larger and better insulated than your nose, there will be pockets that come perilously close to meeting all the requirements for the heat to build up to the point that these chemical reactions meet the criteria for being called fire.

Rats certainly climb. In California, where I have friends and family, rats are a real problem because of all the fruit trees everywhere. Oranges etc. dropping everywhere for a rats' feast. They call them fruit rats but they are just plain old disgusting rats. They are also called roof rats because they climb and then move into your attic crawl space. When you live in California, you have to have an "exclusion specialist" who comes and seals up every tiny hole and crack into your house. It's a standard part of life out there. Otherwise, the rats move right in with you. GROSS!! I have to say that's why I never put kitchen scraps in my compost--just leaves, grass clippings, weeds and so on. I think (hope) it is too countrified here for rats but we have many other animals I don't want to encourage by feeding. I don't even feed the birds anymore. Seed and suet attract too many uninvited guests.