Is this a sign of having termites in your home?

I am living with my mother in her mobile home and it is made of completely wood, no drywall or anything just wood.I have been finding these piles on the floor they look like sand, but they consist of mostly black granules and some tan(like the color of wood). I am not sure what the signs of having termites is but that is the first thing that came to my mind when I saw those piles.Does anyone know for sure if this is a sign?