A bone crusher is a machine that is used to crush bones into small pieces. It's kind of like a really strong blender that can break apart bones like they're made of soft bread.
Now, you might be wondering why someone would even want to crush bones in the first place? Well, sometimes bones are used to make things like fertilizer or animal feed. Crushing them up helps make them easier to use for these purposes.
Bone crushers usually have a big container where you can put the bones, and a spinning blade or hammer that smashes them into tiny pieces. It's important to be careful around a bone crusher because those blades or hammers can be really sharp and dangerous.
So, in summary, a bone crusher is a machine that can crush bones into small pieces, which can be used for things like making fertilizer or animal feed. It's important to be careful around these machines because they have sharp parts.