1 Mechanical digestion is evident, where one can see the breaking down of large food particles into smaller ones after being ground by the teeth. 2  While the chemical changes that take place happen within the body and are not visible.
Using a pre-emergent herbicide around your property could stop these territorial plants from overtaking your home's most valued green space. Pre-emergent herbicide is a type of weed killer that prevents weed seeds from sprouting. Unlike normal herbicide, it is meant to stop weeds from growing in the first place by spraying or spreading a chemical onto the soil so that weeds have difficulty placing down their roots.
How Pre-Emergent Herbicide Works To get a better idea of how pre-emergent works, let's look at 3 key principles of pre-emergent weed control. Principle #1: Pre-emergent herbicides are designed to control germinating weed seeds.