Midrasz do Kapłańska 11:42

The former Rabbis were called Soph'rim, because they counted all the letters of the Torah; for they would say the letter Vav of the word Gachon (belly) (Lev. 11, 42) is just one-half the number of the letters contained in the Torah; the word Darosh-Darash (diligently inquired) (Lev. 10, 16) is one-half of the amount of words the Torah contains; the passage V'hisgalach (then he shall be shaven) (Ib. 13, 33) is one-half of the verses of the Torah. In the passage (Ps. 80, 14) The bear out of the forest doth ravage it, the letter Ayin of the word Ya'ar (forest) is one-half the number of the letters of which Psalms consist; the passage (Ib. 78, 38) But He, being merciful forgave the iniquity, is one-half the verses of which the Psalms consist.

2) (Vayikra 11:42) "that go upon the belly": This is the snake. "all that go upon the belly": to include snails and the like. "that go upon four": This is the scorpion. "all that go upon four": to include the beetle and the like. "the many-footed": This is the centipede. "until all that are many-footed" to include their like. "of all creeping things that creep": to include the worms in the roots of olives (i.e., while they are attached) and in the roots of figs. "You shall not eat them": I might think they could be fed to minors; it is, therefore, written (Vayikra 11:41): "it shall not be eaten."