I've really enjoyed my blue death feigning beetles that I bought from bugsincyberspace about a year ago and thought I'd share some observations. I've had five cuties until a couple days ago where I discovered one had died (I'll post about that separately). Here's my thoughts:
Activity - When I first got them, they were active at first and then abruptly I didn't see them much which was really disappointing. As the weather warmed in the spring and into the summer and my house rose from late 60s/early 70s to the late 70s, they became much more active and I would see them frequently scaling my vertical cholla pieces. Now that the weather has cooled and my house gets into the lower 70s, I have noticed they are less active again. And with the warm spell we've had recently and my house back in the mid-70s again, I once again am seeing them more. I find this interesting since in the wild their desert environments can get pretty cold at night!
Noises - I have been surprised by how LOUD they can be when they "scrape" their little legs on the glass! Mine seem to love "wiping" the glass of their enclosure with their legs as if they are trying to escape. They will sit and do this for a long time, and if their leg parts hit it just right it will actually create a screeching/scraping sound. I also hear thuds every so often when they fall off of tall stacked cholla pieces--I supposed this is somewhat of a hazard, but you think they would have better senses to avoid falling off things! They seem unfazed though and get right up and keep going.
"Coma" - There have been two instances where I dropped a piece of carrot into their enclosure and didn't aim well and it hit one right on the back or head. First time this happened I thought I had killed one--it hit his head and he just flattened down his body and legs immediately and stayed there for a looong time. Next day he was moving and back to normal, so I think this is related to their death-feigning predator response. I don't drop food in anymore because I could easily hit them at just the wrong angle and not be so lucky!
Substrate - I've used only a white fine vita-sand reptile substrate but am going to switch at least part of it to something else because while I love the contrast with the beetles and seeing their little foot tracks in it and watching them dig it under cholla, there are some big downsides. The biggest is that anytime they are eating a jelly or very moist food, the beetles get the moisture on their feet and then when they step into the sand, the sand granules accumulate on the tips of their feet and hardens. I can tell it drives them crazy because I see them rubbing two legs together trying to get it off. A couple of times I have had to grasp their bodies, hold them over water cupped into my hand, and dip the ends of their feet into the water--they move their feet and the sand slowly dissolves. Another downside to the sand is also that it sticks to the food, and I worry that they might accidentally ingest it at some point. I also find areas of sand that are clumped underneath, kind of like cat litter, and I haven't figured out if they are actually "peeing" in concentrated areas or something or if it's just residual moisture from wet food seeping down into the sand and clumping. And finally, the white sand makes a striking contrast to all their POOP! Yes, they do poop and the little pepper granule-looking things accumulate quite quickly and are easy to see!
"Itching" -Something perplexing I've noticed is that I occasionally will see a beetle rubbing two of its legs against each other as if it's scratching an 'itch'. I don't see any dried beetle jelly on the legs when they do this, but they will do this for quite a while. I'm not sure why...mites seem a logical explanation but I don't see any and keep a very dry environment so it seems doubtful.
Food - I feed mine 1-2 times a week, and still am not confident on whether they should have constant wet food in there or not. I live in the intermountain west, so things dry out really quickly. My staples are beetle jellies, bits of carrot, and little soft freeze dried dog food capsules from a sample pack that I mush in with some water. Of other fruits and veggies I've tried, they seemed to love blueberries and especially watermelon, probably because of the sweetness. They did not like an acidic fruit I put in there once. I get my jellies from the beetlesource site, and the only one I have trouble with is the healthy pineapple flavored yellow one which always seem to sprout greenish mold bits every time I use it, over multiple orders. All the other ones don't have this problem and work great, but again, being in such a dry area, they still dry out way too fast for me...I've considered having a little dropper and replenishing the moisture with a couple drops after 2 days or so.
Cholla - My beetles are lucky because I have family in Arizona, and they went out into the sonoran desert nearby and cut some real cholla pieces for me. They are a good 2-3 inches in diameter, and I have six pieces in there stacked with some vertical which the beetles just love--they crawl in and out of the holes, scale the tall pieces, and like to hide in the dark middle areas. The only hazard with the really tall pieces is that the beetles just are not very good at not falling. Like I mentioned above, I will every so often hear the thud of them hitting the sand. I have noticed one of my beetles has an antenna that is much shorter than the other, so I worry that they might be injuring themselves a bit. But I hate to take away all the fun surface area for them.
Personality - Before my 1 beetle recently died, I noticed that there was always one loner beetle who was hard to find. I could at any time peek in there and usually find four of the beetles, but the fifth would always be hidden somewhere or off by himself. The other four would often be huddled together or resting in the same area--evidence to me that they are somewhat social and somehow find each other.
Vibration - They are very sensitive to vibration and I sense that this is how they navigate and communicate with each other. Just my going up to their enclosure and speaking close to the glass can sometimes be enough to make them grimace, and they hate when I take off the metal mesh lid which creates deep scraping and vibrational noises.
Here's a couple videos I've posted (should've muted the background noise):
Silently "wiping" the glass https://www.youtube....h?v=QPloTsjLjtI
Enjoying cholla: https://www.youtube....h?v=fmpTNni6H0Q