The roach could walk away or fly or run if it chose to, but it doesn't choose to, because the venom nixes its motivation to walk, and only that.
蟑螂如果想的话 可以选择走开，飞走，或跑开， 但是它没有选择这样做， 因为那个毒液使其丧失了走的意愿， 只是那样。