RE: Pet food quantity - large package or small package?
I buy in bulk and use airtight containters. That way, I can get the bulk discount, not have to worry about buying pet food for a couple months at a time, and have food that my cat Jane is happy to eat. Everybody wins!
Aside from the financial aspect, Jane has a tendency to get very upset if she doesn't know that there is lots of food around for her. It makes her feel safe. When we first got her, she had a regular food bowl, and she would vomit around the house and try to hide it for later, just in case. I switched her to a feeder that holds about two weeks' worth of food for her, and it has majorly cut down on her puking. And she looks less anxious overall, so long as I make sure it's always full.
Sometimes, if I forget to refill her feeder for a bit and she gets to the end, she will refuse to eat the last bits. I don't know if its because of staleness, or her fear of being out of food. The world may never know..