Q. Why is honey kosher? It must be because it is mentioned in the Torah.
A. Well, not really. There are two references to dvash (honey) in the Torah and although the word honey is used, the Gemara explains that it is actually a reference to date or fig honey. This does not mean that honey is not kosher. The gemara discusses this too and explains why bees are not kosher, yet the product they make is kosher.
The Mishna in Tractate Bechorot (5b) says: "That which comes from something which is not-kosher is not-kosher, and that which comes of something which is kosher is kosher."
The Talmud (Bechorot 7b) quotes a Beraita which says, “Why did they say that honey from bees is permited? Because even though they bring it into their bodies, it is not a product of their bodies.”
The sages all agree except for one rabbi named Rav Yaakov. Rav Yaakov has a different explanation as to why bee honey is kosher. He has a different approach to the original prohibition that the sages based their ruling on from Vayikra 11:20 (Leviticus 11:20). Rav Yaakov explains that flying swarming insects are not kosher but the prohibition does not extend to anything they excrete.
Vayikra 11:20 (Leviticus 11:20)
11:20 All winged swarming things that go upon all fours are a detestable thing unto you.
11:21 Yet these may ye eat of all winged swarming things that go upon all fours, which have jointed legs above their feet, wherewith to leap upon the earth;
11:22 even these of them ye may eat: the locust after its kinds, and the bald locust after its kinds, and the cricket after its kinds, and the grasshopper after its kinds.
11:23 But all winged swarming things, which have four feet, are a detestable thing unto you.