It is just fecal matter which is undigested food waste.
pick it up
no, more
Clean it off.
Wont eat or talk. Or poop.
Both male and Female guinea pigs sometimes eat their droppings. the reason is that their poop contains minerals that are helpful to the guinea pig.
THIS IS TRUE! they are trying to poop but the poop wont come out.
Either leave it, it should come off in the sawdust or wood shavings, whatever is in your guinea-pig's cage, or, you can pick up the guinea-pig and flick it or pick it off.
its either you fed it to much or it has a disease
Because it doesn't really care as long as it is reasonably dry and warm.
probably not but he should be dewormed now.
Most likely
This pet may be sick. A trip to the vet may be a good idea. (it most likely has diarrhea)