No, as an inanimate object it wont scare away pests, maybe crows.
Garden gaing balls are desinged to scare away birds and other pest.
Fences, nets, and repellants are used to keep garden pests away. They help in keeping pests such as birds, squirrels, opossums, and even certain insects away from the garden.
Loud noises will get rid of most bird pests, but if you have neighbors, you could try trapping and relocating birds. Reduce items such as water and food sources that would attract birds. Balloons or reflective streamers can also scare birds away.
Garden snails !!
Termites
They eat pest insects that would harm your garden.
slug, i think!
arachnid ant aphid
You can try Fertilo which is a very organic pesticide. There are plenty of other means that can keep you and your garden safe from pest.
It would help but no it can't completely keep it pest free
Crows, aphid
spitter bug