Why won't my beardies eat ...?

My bearded dragons used to be eating crickets about 8 months ago ( they are 1 and a half yrs old) but they totaly refused crickets so i had to move onto locusts, but as many people know when buying crickets your get move for your money, does anyone no how i can get them to eat crickets again ? obviously i don't want to stave them i just would like them to get a few more a week =D please helpppp