I have not heard of people needing thermometers to check their worm bins, unless maybe with large commercial bins. I'm thinking that compost thermometers are used in hot composting to make sure things are heating up the way they are supposed to. Worm composting is not hot composting.
Mostly the concern with worm bins seems to be with the ambient temperature--making sure the worms don't freeze in cold weather or overheat in the summer.
How are you thinking of using the thermometer? To make sure the bin is NOT heating up? That might not be a bad idea. But it definitely isn't necessary.
mbetts

I don't use one either (I think that's the main reason you haven't gotten much response.) There's no reason a meat thermometer wouldn't work that I can think of.

There's a guy in Arizona who regularly checks the temp because his bin is in an un-airconditioned shed/building. He's got a cooling system pumping pond water from his fish pond right next to the worms through coiled copper tubes running through the bed. His pump failed and by the time he found out, the beds were 130 degrees! It was something like 113 outside. I'm sure the shed was worse. Amazingly, he still had a few worms that were alive. That's a situation where I'd use a thermometer. My indoor bins aren't in much danger.

Thanks for your responses. I've been finding my worms in the bottom drain tray and in the condensation corners of the roof, so I thought they were trying to escape excessive heat. The worms in the bin hardly move when exposed so I worried about that too. (sigh) Guess I am just beng an over-protective Newbie.

Some of my worms also like to live in the drain tray, but there are plenty more of them in the other trays. And they are active.
I think it is worrisome that your worms are not active. Were they active until recently? And what is the weather there?
If you are in zone 10, it probably is darn hot where you are. Do you have them indoors? If they are outdoors are they protected from the sun?
And they should have some air circulation.
What does your bin smell like? Is it getting a sour smell? If so, or if the stuff in the trays is soggy, you need to get some water out and get some air in there. It's hard to know without seeing your bin, but I am inclined to think you need to take off the cover for a while, and add some dry material, which will both soak up some of the water and get air in the bin.
And if it is swelteringly hot, then you may need to bring the bin inside, or search this forum for some of the things people do who live in Texas!
Good luck, and let us know how it goes.
mbetts

My Zone 10 is in San Francisco, not Texas. And I'm very near the bay, with cool breezes and fog. My Worm Factory is outside in a protected patio. We've had some unseasonal hot weather, and on those days I've removed or propped up the lid to keep the interior moderate. The bedding has always been damp, but never wet. However, the day after the last feeding, it did start to smell sour for the very first time, and I also saw flies and little scurrying things. I had put used paper towels over the food, so thought that might have kept the air from circulating properly. I removed that and replaced it with more shredded newwspaper.

It is still smelling off, so I am going to remove the new food and let things rest for a few days. The food was some frozen peas that had become unfrozen and left outside for a few days. And there was some old tofu mixed in with it all.

Up until this last feeding, everythng was going along smoothly. And I was enjoying the faint, fresh, earthy smell that greeted me each time I fluffed the bedding.

How active should the worms be? They do move, just very slowly. I'm hoping that I just have lanquid worms.

Folly

Hi there. I'm fairly new to worm composting, have had a worm factory in operation since April 2008. Far from an expert! That being said, here's my 2¢. The food could have gone rancid quickly in the heat, and the worms may have had a hard time getting through a pea's outer coating. Also, the tofu is protein and so that probably contributed to it spoiling quickly. If you add a lot of shredded newspaper to the top of the bed, I'll bet the fly problem lessens. When the bin neutralizes, chop up the food well and bury it deep with plenty of shredded newspaper on top. Good luck!! Have you started using the meat thermometer? Might be interesting!

I live in Davis, CA - so you know it gets a LOT hotter here than the Bay Area. My bin is on the patio in the back yard where it is in deep shade all of the time. When we are in the 100's, the worm activity slows down, but I haven't seen any great die-off. If it's very hot I take the lid off (I have a Can-o'-Worms) and mist it regularly so the shredded newspaper doesn't dry out - then put the lid back on when the temps cool in the evening. But honestly, I'm not diligent enough to do that every day.

I removed the food and added more dry shredded newspaper. By the next day the smell and extra bugs were gone. To make amends with my worms, I added a small amount of cut up watermelon rind. My guys made a stampede to the new food and I could tell that they were very happy from all the wriggling. Watermelon as an aphrodesiac? :-)
-Folly

I use bottles of ice on top of my bin to keep it cool. I live in Florida, and my worms are in my hot garage. They love the frozen bottles. I put them in the bins, but on top of some paper. I worry about a worm sticking to the frozen bottle. I always find them up near the top when I change the bottles. They seem to be flourishing with a cool zone to hang out in.

I do the same as jenv14. I put a frozen water bottle on the top when I go to work, bring it in when I get home, and freeze it overnight. My worms are growing, eating, pooping, and doing other wormy things.