That family comes from under-feeding them. Follow these steps:
1. Allow all hungry hearts to empty.
Note: Keep some happy hearts full at all times.
2. When they beep for attention because they're hungry, don't feed them.
3. After some time, they will appear angry with you, but don't feed them.
Note: It may take 15-30 minutes from the time they call for attention until
they appear angry with you.
4. After some more time, they will appear no longer angry with you. Now,
feed them a meal that will fill one hungry heart.
Note: It may take 15-30 minute from the time they first appear angry until
they no longer appear angry.
Note: The attention icon may remain lit after they no longer appear angry
with you, before you've fed them anything.