What devices allow the slug to climb the sheer blades of grass and, without getting hurt

What devices allow the slug to climb the sheer blades of grass and, without getting hurt, crawl even through the blades of a sharp knife?

Let’s take a closer look at the mechanism of movement of the slug. By what means is he moving? – Due to the effect of suction to the surface and lubrication of the surface with mucus secreted. The secreted mucus, in particular, makes it possible to reduce the friction force, because it is located between the motor apparatus and the surface. Hence, it can be concluded that the composition and amount of this mucus is sufficient so that there is no direct effect of the sharp edge of the surface on the locomotor apparatus of the slug.