Bearded Dragon Feeding Behavior & Bricks

I recently switched my pair of Bearded Dragons to a larger enclosure as they are growing at a nice rate. In the enclosure I included two fairly stout climbing/basking branches, and several bricks piled up to make a nice basking platform (and seconding as a place to rest those branches).

The bricks are old red bricks, previously used; they are covered in places with some remaining traces of mortar. While they are pretty much free of the mortar those remaining traces are there and are quite visible - not only to the human eye but also apparently to the eye of the dragon! As soon as the beardies were in there with the bricks, the female started to munch on them like crazy. I do not know if they are naturally attracted to lichen (the mortar traces kind of look like spots of lichen) or if they normally browse on sandstone - but she sure went at it. A few days later the male was doing the same thing, and I have seen both do it since. They sometimes go for the mortar where it is evident, and sometimes for the brick where no mortar is evident at least to my eyes. They scrape at it with their teeth for up to 10 minutes at a pop.

My bearded dragons get vitamins in the form of well nourished crickets, well nourished mealworms, a large variety of greens from the fridge and from my back yard (chemical free), and also get some flowers and a bit of fruit. The crickets get to eat: greens, potatoes, left over fruit, turtle pellets, dog biscuits, vitamin powder and clacium powder - and they thrive - and so pass on these nutrients to the dragons. The bearded Dragons also get their veggies sometimes dusted with calcium or with vitamins and trace elements. I am pretty certain that there is no vitamin or mineral deficiency.

So - I am wondering - is this a normal behavior - or do bricks just have some sort of abonormal attraction for Bearded Dragons?

Best regards,
Glenn B

I'm not sure what they are trying to get out of it, but I would remove the bricks for the sake of the beardeds' teeth. I use parts of cinder blocks as furniture and have never seen a dragon try to eat them. I would just be concerned about the dragons dulling or breking their teeth. It could be the color they like. In any event, I would remove the bricks, and replace them with perhaps cinder block, or small blocks of concrete, or just stone from a landscaping supply store.