In verse 29, it states that the creeping thing that creeps are the mole, mouse, large lizard, gecko, monitor lizard, and chameleon. Verse 43 states that one shall not make themselves "abominable" with those creatures, nor shall they make themselves unclean with them because he or she could become defiled by them.
I'm starting to believe from what I've been reading here that being unclean has less severe consequences than doing something abominable. I think something that's abominable is what is detested by the Lord. There's a verse in the Bible that states God hates seven things: a few of them I can remember off my head is lying and a prideful spirit. I can understand that having a prideful spirit will actually keep one's heart and mind off the Lord.