Is there another way to say "killing two birds with one stone?"

We were killing two birds with one stone, but given the circumstances, I wish I could think of another phrase.  You see, we needed to make space in our freezer for the ice cream sandwiches Cat sold for a soccer fundraiser, so I had to get out the old hamburger buns that I'd stashed in there.  And, we needed something fun to do, so we used the buns to feed ducks at a duck pond at a beautiful park called Nielsen's Grove.  The kids weren't excited but they all really had a great time.

There were at least two different kinds of ducks (I don't know the names, but some were white and others were various shades of brown) and lots of ducklings, plus some other smaller birds.  We saw some of these cool Yellow-Headed Blackbirds, too, which was very cool.  They were taking bites right from Cat and Eliza's hands, and Luke started following one around.

I don't think Luke has ever fed ducks before, and at first he was happy to watch his siblings feed the ducks while he nibbled on the old buns.  But once they taught him what to do, he was feeding the ducks too.

Luke and Eliza took to naming the ducks, and some of the names they came up with were Squeaky, Lightning Bolt, Big Black, Creepy White, and Ghost Group.  Once we'd used up all of the buns, we sat down to have a picnic lunch but Eliza and Jack were more interested in feeding the ducks than eating lunch, so they continued to feed the ducks their peanut butter sandwiches, baby carrots, and apples.  Supposedly, the ducks ate those things too.

When we were finishing our lunches, I asked Cat to take some pictures of Luke and me and she did a great job.  I had to include my favorites.  I'm seeing another trip to the duck pond in the not-too-distant future, I think.