Shemini 11:03, 09, 13, 22 The Signs of Tahara (Kosher) for living things (Yeshiva 5781 / 2021)(02)

11-03, 09, 13, 22 The Signs of Tahra (Kosher) for living things (Yeshiva 5781, 2021), Class Two.
Cont.
1) Chewing cud (review many times) and split hooves (not actually touching the ground, divided, many Midos).
2) Scales (separation from environment and protection) and fins (growth), the first determines the second.
3) Birds cannot be predatory, because we will develop their evil character. The other signs (?).
4) Insects firmly planted on the ground, wings covering the entire length (Tznius).
Some of the ideas here lack a source.