Arachnid aficionados say although male tarantulas spend most of their lives in their underground burrows, they leave them to find female tarantulas once they reach sexual maturity. Male tarantulas are typically low on fuel during mating season, as they aren’t eating or drinking at all, according to Dallas Haselhuhn, who studied Colorado brown tarantulas during his graduate program at Eastern Michigan University. And while climate change has notably been affecting other species, Colorado tarantulas may be more primed to handle it, Haselhuhn told NPR’s Short Wave . The amount of eggs that hatch depend on the female tarantula’s size or how much food she has, but range from about 100 to 400, Shillington said. Shillington said she still doesn’t have answers on how far male tarantulas travel when they’re mating, or what triggers them to leave.