All guinea pigs eat their droppings. The guinea pigs digestive system is different to ours and all waste must be digested twice to absorb all the nutrients. Don't be worried as this is a perfectly normal thing to do.
Raccoons will kill and eat any bird, guineas included.
yes
Yes
Rodents do eat their own droppings, yes.
yes. they take nutrients from soft droppings which they take directly from their rear end. they don't eat the hard droppings.
generally pasta with tomato sauce
No! It is not!
Crabs eat decaying animals and bat droppings.
they eat human droppings but they also eat walnuts and grass
Animal droppings and bugs.
they eat the juice off the grss and tiny droppings off insects
Sure, you can eat broken glass, too. Neither are good for you.