for fun play mind games?

thats obvious! its a colony of unicorns! the more unicorns you steal from the colony the bigger bag you will need to hold them all until you had so many years that you get really fat and end up draging the sack everywhere you go but the unicorn colony still is on the look out for you so you grow a beard and mustache and dye your hair all white and start wearing red jumpsuits and change your name to Nicolas and join a gang of midgets where everyone calls you Santa. From there you begin a large multi-million dollar company producing toys and are forced to move out of country because of the too big demand of your toys. but by this time all the unicorns youve stolen have begun there own colony and evolved. you install a tracking system on each one so that they all have antena on their head. you drag them around pulling a sleigh and make annual trips to the country to get food for the up and coming year ahead. by this time you are well known, even though your location is still undiscovered. you and your gang of midgets are slowly taking over the world.

and that is the answer to the riddle.

Footsteps!

the more earth you take the bigger the hole you leave behind?

a hole