The Monsanto Insectarium is an insectarium located within the St. Louis Zoo, in St. Louis, Missouri. David Mason & Associates designed the $4 million, 9,000 square feet (840 m²) facility which opened in 2000. It houses educational exhibits and an active breeding and research facility. The research facility includes a window to the exhibits area and two-way communications so visitors may watch entomologists work and ask them questions.