On the closing daf (=page) of Perek (=chapter) Eilu Terefot, the Gemara turns its attention to the passage in SeferVayikra (11:42) that forbids eating a variety of different insects and creatures that crawl on the ground.
Our Rabbis taught: “Goeth upon the belly” means the nahash, the snake, “whatsoever” includes the shilshul, the earthworm,
and all that are like unto it. “Upon all fours” means the akrav, the scorpion, “whatsoever” includes the hipushit, the beetle and
all that are like unto it. “Hath many feet” means the nadal, the centipede, “whatsoever” includes all that are like
unto it and all that resemble the latter.
The shilshul or earthworm – lumbricus – is found on every part of the globe. It has neither eyes nor legs (it crawls) and it likes moisture. By its burrowing actions, the earthworm is of great value in keeping the soil structure open, creating a multitude of channels which allow the processes of both aeration and drainage to occur, helping plants grow.
There are a number of different types of akravim – scorpions – that differ mainly in the strength of their venom. All known scorpion species possess venom and use it primarily to kill or paralyze their prey so that it can be eaten. A scorpion has eight legs – four on each side. Some suggest that when the Gemara says that they have four legs it means that they possess four pairs of legs.
The hipushit, or beetle – coleoptera – is the largest group of insects. In Israel alone there are about 3,000 types of beetles. Its body is made up of a head, thorax and abdomen, it has two sets of wings and three pair of legs.
One of the most common of the nadalim, or centipedes, is the Scolopendra singulata whose body is made up of 22 segments, with a pair of legs extending from each segment. Attached to its head are two venom glands that help the animal to kill or paralyze its prey.
As the Gemara concludes, all of these creatures and all that are similar to them cannot be eaten.