Travel back in time with “DinoRoars”—a self-guided safari around the Smithsonian’s National Zoo—and meet massive animatronic dinosaurs that move and roar. From June 1 to August 31, visitors will be able to look up and listen as the roar of a 39-foot-long T. rex joins the symphony of Zoo animal chirps, squawks and chuffs. On exhibit will be Compsognathus, Dilophosaurus, Parasaurolophus and babies, Stegosaurus and baby, Quetzalcoatlus and babies and T. rex. Each dinosaur is fitted with electronic brains to activate and control movements and produce the sounds. Admission to the Zoo and “DinoRoars” is free.