Reptile & Amphibian Forums

A few weeks ago, we had some discussion about the possibility of ground walnut shells expanding significantly on exposure to liquid. The concern was that if a snake were placed in a cage with ground English Walnut shell substrate and accidentally swallowed a piece of substrate, the shell piece would expand in the snake's stomach and cause impaction. The ESU Lizzard Litter that I bought claims on the bag that these pieces won't cause grave danger to a snake if swallowed. Others say that their herp vets warn them against using this substrate.

I did a little test just to get a better feel for what I was hearing. I took about 50 of the little pieces of walnut shell and soaked them in water for two weeks. I used a little plastic lid from some spray bottle that was sitting around. I think I've had them soaking for about two weeks. I checked them tonight, and I don't see any evidence of swelling of the little pieces. I took a picture to compare a dry piece with several pulled out of the water.

I'm not saying that this test is conclusive or even particularly strong. However, I think it offers some evidence against the idea that these pieces swell badly when exposed to liquid. A snake's digestive system has much more than just water, and the acids may break down the shell pieces enough to let water soak into the "wood" more effectively. Then again, breakdown of these pieces by acid may simply lead to faster decomposition of the substrate piece.

If I use this substrate, I'll certainly try to keep my snake from getting any of it on his food. I don't like the thought of letting him eat substrate, but I'm more likely to give the substrate a try.

Thanks,

Bill

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It's not how many snakes you have. It's how happy and healthy you can keep them.

that stuff reminds me of pea gravel with sharp edges/corners i would'nt even give it a try, no way.

agreed. also some pieces are larger than others. Err on the side of caution. English walnut shell not found near California!
Todd Hughes

I have seen large english orchards in calif, one strange thing about it is they are english tops grafted onto native trunks and they produce english walnuts not native walnuts.

Too weird, man! Oh well, can't get 'em all right!
Todd Hughes

holbrooki, i dig dem yellow bellies!

Grafting is a pretty standard thing in all tree crops. You get the fruit you want, and a disease/pest resistant root stock. If you have any type of fruit bearing tree in your yard, it's most likely been grafted to a special root stock.

As far as the original post, nut shells aren't the same as wood, and don't go through any significant shrinkage due to moisture loss after they are harvested. The nut meats do lose moisture and pull away from the shell.

The shells are really more analagous to ceramics than they are wood.

agricultural botanist, neato!

Nope, just a guy that's lived around tree crops his whole life in California's Great Central Valley.

Almonds and walnuts are pretty big here.

in silicon valley where i grew up, then came the computer age and the most the orchards got converted into housing tracts and industrial parks.

Sadly, it's happening here as well. I recently took a drive down a road that used to be nothing but orchards and pasture with a canal running alongside it. Now it is almost McMansions for its entire length.

It's all these people pretending to be "developers." They are really just ag land destroyers; "developer" sounds nicer though...

The fact that it isn't found near California wouldn't necessarily bother me. Does California really have that many coconut trees? I have huge amounts of ground coconut in the cage. However, with the overwhelming consensus against the walnut shell substrate, I'll not use it.

Thanks,

Bill
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It's not how many snakes you have. It's how happy and healthy you can keep them.

Thanks for the feedback. I can feel that it's rough, but I wouldn't have thought it rough enough to bother a snake. The overwhelming consensus is against it, so I'll not likely use it for the snake cages. Maybe I can find some other use for it.

Thanks,

Bill
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It's not how many snakes you have. It's how happy and healthy you can keep them.

back in the early 70's i used to keep large pythons and common boa constrictors on ground corn cobb, after spending hours picking that stuff out of their mouths, i decided to keep my snakes on newspaper. Now days i only use very soft and fluffy pine shavings or an occasional paper towel if i have a young individual who needs close observation, Happy snakekeeping!

What is the primary advantage of pine shavings? I've heard some people say that pine could cause some of the same problems that cedar does and others say that the two substrates are completely different. Did you hear something specific that made you feel good about pine or have you just proven its safety through experience?

How deep do you make your substrate? If you were going deeper or shallower, would you use something else?

One more thing, if ground walnut shells are really the danger that we're hearing (and I have no reason to doubt what I'm hearing), why don't we hear the warnings against it that we hear with cedar? I did pretty good reading to prepare for owning a snake, and I don't remember any strong warnings against the ground walnut substrates. I would think that the community would put out that warning in the same way that it warns newbies against cedar. I think we need to make that warning as common as the cedar warning.

Thanks,

Bill

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It's not how many snakes you have. It's how happy and healthy you can keep them.

the pine shavings i use are soft and fluffy, much better than the aspen at petco or petsmart. I've used pine for years and my snakes have never had a problem with it. Ofcourse i can see why someone would not like pine shavings as a substrate for a display tank.

The particles could get interally lodged because of the sharp, jagged edges, not because of the potential to swell up. Impaction isn't the only concern here; those particles would literally shred your animal from the inside, which paves the way to infection and chronic bleeding. I honestly can't think of a more dangerous substrate to house reptiles on except for perlite which is a volcanic glass. (Nothing against perlite. I've used it to successfully incubate eggs, but people have a tendency to confuse incubation media for laybox/housing substrate.)

With that said, please don't ever listen to whatever the product label advertises. There is no FDA regulating the sale of reptile products, so there's nothing stopping those companies from outright lying about what they're trying to market. You can find a cheaper alternative for just about every manufactured reptile product at Home Depot or Walmart, but people prefer to think the version that has a picture of their animal on the bag is the better choice.
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www.BugChick.com

chickabowwow

Just chiming in to agree-over the years I've seen MANY snakes and lizards fatally impacted with ground walnut shell substrate. The stuff should be banned!

Brad Chambers

Thanks for adding your opinion to the consensus. I think we live in a world with too many laws already, so I'd not support a new one to ban walnut shell substrates. However, if this stuff is really that bad, I don't understand why caresheets don't warn against it as they do cedar shavings. While there are likely some people who buy snakes but don't research and end up using cedar substrates, they are few. Because cedar has such a bad name, none of the reptile supply companies make a cedar substrate for snakes. I don't understand why ground walnuts don't have the same reputation and therefore the same pressure against companies selling it for substrate.

Thanks,

Bill
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It's not how many snakes you have. It's how happy and healthy you can keep them.

Thanks for the clarification. I had originally understood that the problem was swelling. I'm not sure whether the person warning me was in error or whether I just misunderstood. While the stuff doesn't feel that bad to me, I'll avoid it. The swelling issue was something that I could test to some extent without any exposure to my snake. The sharpness issue is one that I can't test without exposing my snake, and I don't want to do that kind of test on my animals.

Actually, I trust word of mouth more than I'd trust a herp version of the FDA. Anything that relies on a bureaucracy is going to be ineffective in the long run.

How deep a substrate do you provide for kingsnakes to burrow? What Home Depot product do you use to provide this substrate?

Thanks,

Bill
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It's not how many snakes you have. It's how happy and healthy you can keep them.

I've never heard of the expansion issue when exposed to water however I do remember someone telling me that some tests showed that the walnut substrate was EXTREMELY flammable. Because of the potential flammability issue I decided to cease experimenting with it. I had tried it briefly as a substrate for some lizards.
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Matt Campbell

Big animals, little animals, plants - right down to the sea itself. We need them, not just for their own sake, but because all this has to be here for everybody forever. Only one thing is certain: if we are to preserve our environment and save this priceless wildlife we need much, much more knowledge.
Harry Butler from 'In the Wild With Harry Butler' 1977

Thanks for adding another thought to the mix. To be honest, the flammability issue surprises me a great deal. I would think that starting a fire on something as compact as the ground walnut shells would be much tougher than starting the same fire in aspen shavings. The area to volume ratio should be higher for the aspen. Are you certain that these tests were comparing ground walnut to other reptile substrates?

I know that ground walnut can be used as an abrasive blasting medium in competition with things like sand, calcium carbonate, and garnet. I would expect the ground walnut to be more much more flammable than these substances because it's a wood product instead of a mineral. However, abrasive blasting involves propelling the particles at tremendous speeds and causing them to have multiple impacts. My substrate is not going to be moving most of the time and will only move slowly when my snake is pushing it around. From what others are telling me, this slow movement doesn't mitigate the abrasive qualities, but I'm still having a hard time seeing where the stuff could find the energy in a cage to catch fire. A UTH or light bulb could never generate the heat of an abrasive blasting gun.

In any case, the warning is interesting, and I appreciate your taking the time to post it.

Thanks,

Bill
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It's not how many snakes you have. It's how happy and healthy you can keep them.

I believe the walnut shell substrate caught fire as the result of a malfunctioning heater of some sort. The problem though was that many of this individual's cages were using the same substrate and when the fire spread it somehow affected those cages as well and ultimately resulted in a total loss of some significance. I'm remembering all this heresay, but I suppose if the ignition temperature for walnut shells were lower than for a wood substrate such as aspen, cypress, or other bark chips, well, who knows. Mainly, I just don't even consider using the product anymore not so much because of one account of a flammability issue but because I find it about as natural looking as aspen. I use only cypress or pine bark mulch with my various herps. I also use just plain dirt mixed with sand, bark, and litter such as leaves or sphagnum moss.
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Matt Campbell

Big animals, little animals, plants - right down to the sea itself. We need them, not just for their own sake, but because all this has to be here for everybody forever. Only one thing is certain: if we are to preserve our environment and save this priceless wildlife we need much, much more knowledge.
Harry Butler from 'In the Wild With Harry Butler' 1977

Again, the idea of the walnut shells being more flammable than other substrates is counterintuitive to me. I'd be more likely to believe that whatever started that fire would have done the same on any other substrate, but I'm open to contrary evidence.

From what I'm hearing, the ground walnut shells are not a good substrate, so I'll not use them.

You mentioned using "plain dirt." Do you just dig dirt from your yard or are you talking about the topsoil available at garden or hardware stores? I like Eco Earth, but the time required for a brick to expand can sometimes be a pain when I'm trying to set up a cage after cleaning. Regular topsoil from Home Depot might be more convenient. If my snake liked it as much as he likes the Eco Earth, I'd consider using it.

Thanks,

Bill
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It's not how many snakes you have. It's how happy and healthy you can keep them.