hello. what size tank do you have? i used to have several burundi fronts in a 125 gallon, and did not find them to be too bad about digging.
the best way to do fronts is to buy 8-12 young (1-1.5 inch) individuals. feed good pellets, mysis, etc. and remove your males as they sex-out.
what you want to do is basically have 1-2 males per 7-10 females. having too many males causes aggression problems. HTH
M