Two cats perch on a stack of pancakes; a young girl climbs on piles of green peas. These may sound like scenes from a surrealistic bedtime story, but they are subjects in Erica von Schilgen’s mechanical collages and drawings. In “Mechanical Migration - a flight of fancy,’’ cranks, pulleys, and music boxes animate the images and characters with help from visitors, who are invited to “play’’ with the pieces. Von Schilgen grew up on a farm with a barn full of greasy chain saws, old car parts, and broken machines, which inspired her creations. Nov. 5, noon-6:30 p.m. (through Nov. 22). Free. Gallery 263, 263 Pearl St., Cambridge. 781-393-0000. www.gallery263.com