B. albopilosum sling colouring

[Katy]

I just recieved a B. albopilosum sling, 3/4" legspan, and I can see a dark spot on the top of the abdomen. I've never seen one before, so I'm just wondering if this means it's about to moult or if this is the normal colouring?
I don't have a picture, my camera isn't good enough to focus on something that tiny.

Thanks!

 

[Katy]

Ah, nevermind!
I'd thrown a pinhead in there, and I went to take it out just in case it was about to moult, and it was being eaten. Well, I learned something today.