All you need are a couple of pre-packaged snacks and some double-sided sticky tape. (Note: if you don't normally put packaged snacks in their lunch, you'll want to start this a few days ahead to set up their expectations.)
Carefully open the snack bag so that the opening remains intact but separated:
Next, switch the contents or add something different, like raisins. I might even add a small trinket this year...
Next, reseal the bags with a strip of double sided clear tape. Wha-la! Instant lunch fun. If only you could be a bug on the wall to see their face when the prank is detected...
P.S. Don't worry if the packaging isn't perfect. Remember they are at lunch with a room full of distracting noisy other kids. Chances are, they'll be too into their normal lunch routine to notice subtle differences they weren't expecting...
P.S.S. This "trick" is fun any time your family needs a little surprise in their routine. No need to wait for April Fool's Day!
