Racing around the woods as a caped crusader or scary skeleton is the kind of fun Elachee Nature Science Center plans to provide during its annual Trick-or-Trek Trail Run next weekend. Participants will dress up in a costume, collect treats and win a prize for best costume all while racing through the forest, across creeks and up and down steep to moderate hills and stairways in Chicopee Woods Nature Preserve. The race is a single and double track off-road running experience.