There’s nothing cooler than catching a glimpse of sharks, penguins and whales at Shedd Aquarium . . . unless you have an antsy toddler that gets tired of staring at fish in five minutes flat. Luckily, Shedd features activities created especially for the preschool set every Tuesday as part of its Tots on Tuesdays program. Look for information about the locations of the aquarium’s countless happenings (which include crafts, story times, animal touch programs, singing and dancing, videos and costumed characters) in the Kovler Family Hall in the main foyer. No advanced registration is required, and Tots sessions occur at various times throughout the day. You’ll still have to pay general admission, of course, but you’d probably sell one of your kidneys to ensure that your smaller tykes are so entertained that you avoid a meltdown during the dolphin show.