This creates practical questions such as: "May a fly be trapped under a cup on the Sabbath?" The "Meno Netziv" says that an animal that is not normally trapped (e.g. a fly, or a lizard) is not covered under the Torah prohibition of trapping. It is however, a rabbinic prohibition to do so, therefore one is not allowed to trap the animal. However, if one is afraid of the animal because of its venomous nature or that it might have rabies, one may trap it. If life or limb is threatened, it may be trapped and even killed if "absolutely" necessary.