The San Antonio Zoo is offering free admission to teachers through the end of August in celebration of Teacher Appreciation Month. All teachers currently employed at an accredited K-12 public, private or parochial school in Texas are eligible for the discount, according to zoo officials. Lone Star State teachers also can purchase four additional standard admission tickets for half off during the promotion. Teachers need only bring a driver’s license and either a school district ID badge or a copy of their teacher certification to gain admission.