Why don't people check their backyards for chametz?

Question

Private lawns and backyards are part of the home domain.

Some people are stringent to remove even the tiniest, most insignificant pieces of ~chometz from their homes before Pesach. But most of them do not seem to care about chometz on their lawns. (Exception: Some authorities do rule that one should check one's garden for chometz, especially if they have little kids. [Source.])

I recently asked someone why most people don't care about chometz on their lawns. He gave me an explanation I didn't understand, about birds eating the chometz.

1. What was his explanation?

2. What, if any, are other answers to the question of why "the backyard doesn't matter" for Pesach cleaning?

3. How can all this be reconciled with the idea that we must not have chometz in our bird feeders during Pesach?

Answer 1

Explanation

Your friend's explanation has its source in the Gemara, Pesachim 8a. "Rava says: A courtyard does not need to be checked for chametz since crows are to be found there." This is the accepted Halachah.

Details

Your lawn is your domain. You may not store chametz on your lawn over Pesach, just like in your house. However, we must understand why we check our homes in the first place. We can then see the difference when it comes to lawns, which do not need checking (as well as why we empty bird feeders anyway).

Earlier on, page 6b explains: When we search, we need to nullify the chametz (declare it ownerless and like dirt) as well. The Gemara asks: Why? If it's about crumbs, who cares? They are worthless anyway, and need no nullification at all. So we say that maybe (by accident on Pesach) we will find a "gluska yaffa" (tasty morsel of cake or challah) and want to keep it even for a moment. So we need to nullify it all beforehand, so that at the moment you find it, it is already nullified. (Rashi)

However, it is obvious that larger amounts of chametz (greater in size than a stray gluska yaffa) will be removed or sold beforehand. Those things won't be missed easily. What are we searching for with our candle and feather? That stray pretzel which fell behind the couch. :)

In your backyard, you can assume that such random tasty morsels of goodness will be quickly eaten by birds. But a large sack of chametz flour left in the backyard still must be removed or sold! You must check your backyard (without a candle and feather) for such items, unless you never store such things there all year anyway.

That is why bird feeders must be cleaned out, if you use chametz feed. You are not searching by candlelight for a crack in the bird feeder that may contain some tiny crumbs. But you did deposit a large blob of chametz into the feeder yesterday, which was too big for the birds to finish off so quickly. Therefore, you must go back and discard the blob.

Another reason some people strictly remove even small crumbs of chametz (an optional stringency) is this: The crumbs may find their way into food in the kitchen, or a baby may find and eat one Cheerio on the floor. On Pesach, a tiny crumb of chametz, even if it falls into a huge vat of food, renders the entire vat forbidden. So there is an extra stringency to clean such crumbs found in the kitchen / dining-room area. Still, we can assume that crumbs in your lawn will become disgusting, and will not make it to the kitchen anyway, even by accident.