Hay should be the main part of their diet, like 80%. Pellets provide trace vitamins and minerals that they may otherwise not get. I'm not familiar with Pen Pals so I looked it up. It's an Alfalfa based pellet. Assuming your rabbits are still young, an Alfalfa based pellet is fine and should be free-fed while they're growing. Once they've reached maturity, gradually switch them over to a Timothy based pellet that has low protein (14% or less) and high fiber (20% or more). Read the ingredients on the pellet package. Timothy hay should be the first ingredient listed. Timothy middlings is not acceptable, nor is wheat middlings as a second or third listing. "Middlings" is essentially floor sweepings. It's filler. It's okay to give them some fresh vegetables. A leaf of Romaine lettuce, a few stems of parsley, and a leaf of Green Leaf lettuce is fine. Be careful with sugar foods like carrots and raisins. The only "treat" my rabbits get is a pinch of pumpkin seeds per night which they happy dance for. No carrots, no raisins, no blueberries. If they've never had them, they can't miss them. I order KMS Hayloft pellets and hay.