wtf do they do?
how do i use one??

Bumpmap textures are the same as textures but give you the opportunity to add an extra layer that is for bumps (more 3d like). You need bumpmap shaders activated for you to be able to see the bumps.

...Plus, they don't work in 3.8x, AFAIK.

ok thanks i was just asking coz someone said it would make my scales look realy cool(to bad my crapy videocard cant support shaders)