20+ Instagram Pics from The Set of 'Pretty Little Liars' Season 4

If you follow any of the Pretty Little Liars on Instagram, you know that they are huge picture-takers. And so in honor of tonight's premiere, we put together a gallery of the PLL ladies' best Instagram pics taken on the set of season 4. From playing dress-up to having some pizza with Mona to pranking their hot male co-stars (Ian Harding, Keegan Allen and Tyler Blackburn, we mean you), see the best of the best pics below!