According to a UPI story, there was a security scare at a Norfolk, Viriginia airport when a British man attempted to pass through a security check point with his robot dog. The robot dog farted at an inopportune time, leading security experts to conclude it was a bomb. At this point, "Dave Rogerson, told the BBC he watched incredulously as FBI agents took a series of swabs from the mechanical toy's rear end." The whole thing sounds pretty unlikely but there actually is (or was) a toy robot dog that farts, the Tekno L1 Robot Puppy. The toy is no longer made so if you want to buy one in anticipation of your next international trip, you'll need to find one on eBay. Also worth noting is that one of the entries in the Viridian Biofuture Robot Dog Design Contest, also boasted this feature.