Eating non edible things is called pica, mostly seen in children. It is not healthy and sometimes can be dangerous. Most commonly it is associated with anemia (low hemoglobin levels). Some times it becomes a habit ( an irresistible urge to do something and only gets relieved after doing the act) which needs to be tackled with habit reversal therapy
Next Steps
consult a Psychiatrist
get blood tests done
Health Tips
read a book "power of the habit"