Need identification of possible pest insect in bioactive vivarium

[AM217]

I was shifting some of the substrate in my Leopard Gecko's bioactive vivarium around and noticed an insect I did not recognize. I Iooked up some common pest insects in bioactive vivariums and didn't find anything resembling what I saw. The only insects I purposefully added are springtails and isopods.

Soil in the area I found them (I actually found two) was pretty dry, so I doubt they came for the moisture.

Attached are some pictures and a video of the insect in question.

 

[AM217]

My vivarium seems to be teeming with life I didn't know was there. Just found another odd insect. Looks like a yellow mealworm except black and smaller.

 

[acpart]

Not a clue. Is that black one moving? If not, it's a dead mealworm! You could see if there's a local field station that can identify insects. Or else you can just watch things and see if they multiply.

Aliza

 

[AM217]

Thought the same thing about the worm, but it definitely moved.

The first one may be some kind of rove beetle (see attached photo), don't know for sure though.