Beareded Dragon making sand pile

My beardie has started piling up sand.Its not really sand its ground up walnut shell but it looks like sand.Anyway Baby started piling it up like a sand hill. Is this normal?

Get rid of the walnut shell substrate , this material will kill your bearded dragon when ingested .
Only good place to that stuff is in the rubbish bin.

No sand , no particulate substrates for bearded dragons as they are all high risk of lethal impaction when ingested if they are unable to be digested or passed.

Who ever told you the stuff was fine for bearded dragons gave you extremely bad advice.

Yes, please get rid of the crushed walnut shells immediately, it has directly killed more bearded dragons than anything else I can think of, no joke. They swallow little bits of it, they can't digest it at all, and it either causes internal bleeding by moving it's sharp edges through their gastrointestinal tract, or it causes a severe impaction and causes paralysis in their back legs because it pushes on their spinal column... Usually they just bleed to death internally. It also harbors bacteria, fungi, and parasites and they all thrive inside of it.

So dump it out immediately, like right now, disinfect the entire enclosure, and put down clean dry papertowels for the time being, and replace them as they get soiled, very easy. You can either keep the paper towels, or put down permanent ceramic tiles or non-adhesive shelf liner. Either way get that garbage out of his tank before you find him dead one morning, I'm not joking, do a search on here for "crushed walnut shells" and do some really awful, sad reading...