The first two trials were in a jar. No contest.
The last four trials involved dropping the Mantis into the web where the spider was laying in wait. One time the spider came to the Mantis, and the Mantis lurched onto the spider when it came in range. The other three trials, the Mantis was on the prowl and sought out the spider. It had a hard time navigating the web (pun intended), but they managed to get to the spiders to finish them off.