And even sea slugs flinch when they know they're about to receive a noxious stimulus.
甚至海蛞蝓在知道自己即将受到有害刺激时也会退缩。
英语百科
Noxious stimulus
（重定向自Noxious stimuli）
A noxious stimulus is "an actually or potentially tissue damaging event." It is a prerequisite for nociception, which itself is a prerequisite for nociceptive pain.
Noxious stimuli can either be mechanical (e.g. pinching or other tissue deformation), chemical (e.g. exposure to acid or irritant), or thermal (e.g. high or low temperatures).