Cressida let out a soft chuckle at Kaden's joke and then gave him a sympathetic smile. Spiders could be very invasive and chances were whatever remnants they would find would be those that were already living there in the first place. The tip she'd given him would chase them away without killing them. There was a delicate ecosystem and while she doubted that students couldn't kill enough spiders to do any serious damage, every little bit that could be avoided was ideal.
Glancing at the clock and knowing she'd need to go to the biology lab soon, she nodded to Micah with a smile, "Good luck."