Thousands of butterflies will be flying freely around visitors at Frederik Meijer Gardens & Sculpture Park.The annual Fred & Dorothy Fichter Butterflies Are Blooming exhibition runs March 1 through April 30.More than 7,000 tropical butterflies will take flight in the 15,000 square-foot Lena Meijer Tropical Conservatory during the exhibition.The 60 species come from Africa, Asia, South and Central America - making it the largest temporary tropical butterfly exhibition in the nation.The tropical conservatory is kept at a balmy 85 degrees and 70 percent humidity to mimic the tropical homes of the butterflies.The exhibition draws in more than 170,000 visitors every year.