First off with the three-year-old it's pretty normal for them to go on hunger strikes, just monitor their weight to make sure it dosen't drop significantly. Keep and eye on the baby though.. Secondly, what are you offering? Live, fresh killed or frozen/thawed? Are you offering mice or rats? Which one were they eating before? Thirdly, what size prey are you offering? This handy chart should help you to choose the right size prey:
And fourth and finally, how are you feeding them? Beeps come out during the night so it's best to feed them in the dark, and some beeps are shy eaters so they appreciate having the prey left in with them to eat. My best example is with Wanda, when we switched her over to rats she wouldn't eat unless we left the rat in with her with a towel over her feeding box to keep it pitch-blackI'd leave them for another week and try again then.