Split a sphere (ai) into smaller versions of itself on collision?

I don’t have any assets so I’m just using sphere’s to work on super basic AI stuff. Sphere’s collide into certain types of other spheres. Is there a way to, on collision, destroy itself then instantiate 5 smaller spheres? Would I just have to have 5 smaller spheres anchored to the inside of the single main sphere? The mini spheres won’t be particles, they’ll just be smaller versions of the larger one.

The best way would probably be to have a smaller sphere prefab. When the object collides, use the instantiate function 5 times, introducing 5 new spheres one at a time. Once it is finished that destroy the main sphere.