If you know anything about DCist, you know we’re suckers for anything the adorable animals who live at the National Zoo are up to. So you can imagine our reaction when FONZ sent out a press release announcing the sale of National Zoo Animal Vocalization Ringtones. Oh, the zoomanity. There are 25 animal vocalizations available for download, each for $2.99. All three of the Zoo’s pandas are on offer, as well as the Sumatran tiger…