This is bananas! Motorists traveling on River Road in Zilwaukee, Michigan earlier this week were witness to a little monkeying around when an electronic message board, used to warn drivers about delays and closings, was hacked by an unknowing prankster, displaying the message: “I-75 close ahead due to loose gorilla.”

According to the Michigan Department of Transportation, the bogus message was not caught by MDOT officials until the following morning, and admittedly, they have no idea how someone managed to hack the sign.

As of now, no criminal complaint has been filed, but an MDOT spokesperson says that they are looking into the incident and doing what they can to ensure something like this doesn’t happen again.

Incidentally, it appears as if the culprit in this little highway prank has gotten away with it. MDOT officials say that’s because in the world of electronic hacking it’s a veritable jungle out there.