WASHINGTON — Who says parking tickets aren’t fun? The Maryland-National Capital Park Police are getting in on April Fools’ Day, issuing parking tickets to all cars parked at public parks.

But drivers should be sure to look inside the envelope — what’s inside is a ticket, but not the parking kind.

Instead of a fine, Park Police are giving out free tickets to the Wings of Fancy Live Butterfly and Caterpillar Exhibit.

The April Fools’ Day prank kicks off Montgomery Parks’ “#ParkKind” campaign, a monthlong initiative to encourage people to be kind to the earth, themselves and others while enjoying the county’s parks.

Every week throughout April (which is Earth Month), Montgomery Parks will host events and activities to thank park patrons for their support. There will be giveaways as well.

So don’t fear the envelope under the windshield! It’s just a friendly neighborhood “thank you.”