The Halacha (Jewish law) that we mentioned the other day in class is that, as we know, one cannot eat Chametz (leavened food) during this week, one cannot own Chametz, and one can't even benefit from it. So how far does that last law—that you cannot benefit from it—go? The following scenario can come up. Shulchan Aruch brings: Am I allowed to feed an animal that's not my own with Chametz that's not my own? Can I pick up Chametz that I see somewhere and feed it to an animal that I don't even own? Shulchan Aruch implies you can't use your own Chametz to feed your animal, but you can't use your own Chametz in the first place. Maybe Mishnah Berurah says it and points it out: that means that if you see a piece of bread somewhere, and you see a bird somewhere, and both are stray, you pick up a piece of bread and put it in front of that bird, even that is not allowed. Why not? Because that too is considered some degree of benefit.
Now, how am I benefiting? It's not my animal. I'm not saving money, I'm not making money, whatever—what's my benefit? The benefit is the joy, the feeling of feeding that animal; that itself is a benefit. So placing food in front of an animal when neither the food nor the animal is owned by you is considered not allowed during this time of year because it's deemed a degree of benefit. Have a great day, come on.