I've noticed my budgies' beaks, especially my boy's, are getting a little long. They have a cuttle bone and mineral block in the cage, but they haven't touched either in the two months they've been here. My girl does like to chew on things a lot, but my boy doesn't really. I used to have a lava rock in the cage that they both used to chew on, but I think my girl started eating it, so I took the rock out. What else could I give them? And how could I encourage them to use the cuttle bone and the mineral block?