After having a night to sleep on it, I realized that I have no objective reason to think that my worms have contributed to our mouse problem. I have found no mouse droppings near the worm bin. We even kept a loaded mouse trap right next to the bin for several weeks, including while we still had known mice, and the bait was not even taken. The sleeping spot I selected as being safe was just a few feet away from the bin, in fact!
I have decided to keep the worm bin for now. However, I have decided to relocate it outside, partly because of the small possibility that it has been or could become a source of food or bedding for mice, but for other reasons as well, which I will explain in this post.
I have had the worm bin, the Worm Factory 360, for nearly 2 years. Years before that, I experimented with a couple of homemade bins. I thought it was time to write an updated review of my experiences with indoor worm bins. I will try and be as objective as possible. Sometimes I think that websites that sell compost products or that promote composting and sustainable living offer too rosy a view of worm compost. I just want to offer an honest assessment based on my experience.
- You can compost some kitchen waste, cardboard, and junk mail year round. The compost never needs to be turned, as the worms do all that. For people who have long winters, they can continue composting even in the winter.
- You get some really nice finished compost to add to your garden. Worm castings are supposed to be very high quality. Sometimes I'm a little skeptical that these worm and organic websites overstate their benefits somewhat. I planted all my garlic bulbs with castings in the fall, and the bulbs do seem to have done exceptionally well, for what that's worth.
- Especially with a shelf-type system (where the worms move up to different shelves), harvest is very easy.
- It may be the only way that apartment dwellers and renters can compost.
- Worms are really interesting to most kids and to some adults.
- You don't need to walk out to your compost pile to compost.
- Indoor compost bins are less likely to attract gross bugs (of course, when it does happen, it's much more disturbing).
- It can be extremely cheap to make your own bin, and it doesn't take much space.
- The bin has an earthy smell. If you don't have a good place in your house to keep it (like a laundry room perhaps), this can be a problem. If you are careful about what you put in the bin, you won't get a really bad smell, but, still, most of us don't want our living space to have a strong soil aroma, even those of us who love to play in the garden.
- It's not for the squeamish. Some people are truly grossed out by worms, so you have to be careful about mentioning it to people. In this way, it can occasionally be a social barrier. Some people may take a "Love me, love my worms" attitude, but for others of us, things may be more complicated.
- Sometimes, gross bugs can show up in your bin. If it's indoors, this can be extra upsetting. Although when done correctly (absolutely no greasy, fatty items or bread in the bin ever), if pests get into your home, they may like your worm bin. This happened to me with a homemade bin, when I was living in an apartment complex infested by cockroaches. There was no food waste in there for the cockroaches, but I did find a couple in there. Maybe they liked to hide or rest in there--maybe they can eat worms. Ants also tend to visit worm bins as well, especially if the moisture level is off.
- It's possible that mice (or rats--shudder) could even use some of the shredded paper to make nests, especially if the top part gets a little dry, and in nature, mice do eat worms. If you are trying to eliminate all food sources during an infestation, this is a problem.
- If you do put the wrong thing in there, you can end up with a very yucky problem. Fruit flies are the most common. The problem is solved by adding bedding and moisture and setting out cider vinegar traps, but it usually does take days to get rid of them all, and they are nasty. If you put anything fatty in there, you could easily attract cockroaches or rodents.
- You are very limited in what you can put in it. Ideally, you need to chop everything up into small pieces and freeze it or microwave it to really compost larger amounts of kitchen waste, so that they break down faster. Onions, garlic, broccoli, and cauliflower cannot be added because they will smell bad as the worms break them down. Citrus is too acidic.
- Growing mold is part of the process. The worms eat the mold. This is probably not good if anyone in your house is allergic to mold, and even in the absence of allergies, it is probably not healthy to have extra mold spores in your house, because you will be breathing them in.
- Worm bins inevitably will have some kind of problems that will have to be troubleshooted, the most common being fruit flies or odors. No composting system is going to work perfectly all the time for all people, and this can be yucky and smelly when the problems occurs in your living space. Some people can't get the moisture level right in their worm bins, or put too much acidic foods in them or something and end up with escapee worms. This has never happened to me, but I would think it would be very disturbing to find dead worms on one's floor.
- A commercially made worm bin can be pricey.
I do recommend a commercially made bin over a homemade bin because I think the chances of success are higher, and harvesting should be much easier. If the instructions are followed carefully, potential problems will be minimized. Composting is always a process of trial and error, and it is pretty much guaranteed that the occasional pest or smell problem will have to be dealt with.
All and all, I am much happier with my outdoor compost pile. It stays moist enough where it could not become a shelter for rodents. (I have simple flexible plastic bins with holes in the side, open on top and bottom, and we get lots of rain here). I do get some larvae and bugs in there sometimes in the summer, but I just see them as part of the process.
I do not have to be overly careful about what I put in my backyard pile. For my greens, I put in all my garden waste, all fruit and vegetable scraps, coffee grounds, and eggshells. For my browns, I use fall leaves, shredded paper, and cardboard (often not even cut up that well). When I turn it once every 3-6 months and start a new one, I really do make a good amount of compost. I use it as more of a top dressing, so I don't worry too much about it being completely finished. Our winters are mild enough that I can add to my backyard pile year round.
I never, ever, ever add animal waste, meat, dairy, or grains to my backyard pile, as I do not want to attract rats, mice, or other rodents. (I did see a raccoon visit it once, after I added a bunch of rotten mangos, which did not make me happy). But, if a mistake is made, it's much more easily dealt with outside, several yards from my home, than it is indoors with my worm bin. I learned to bury things better after the raccoon incident, and to be particularly careful about that when adding large quanities of slightly rotten fruit.
My opinion on worm composting is that it is one interesting option for composting that has its pros and cons. A person has to be very committed (and very crunchy) to keep it indoors. I think a plain old backyard pile is the best choice when possible.