Android build trying to package all assets?

So i wanted to test my android project. I attempted to make an apk build. I noticed that after hitting build unity was trying to include all of the assets i was using, even assets i imported but never used. I thought unity only included things referenced in the scene or that scripts would reference? Just out of curiosity i let the build finish and my apk file came out to be over 1gig, and i know there is only about 70mb of actual assets being used. How can i fix this and/or what do i not understand here? thank you for your time and responses!