Belladonna is a toxic plant for pets and humans. The plant is poisonous when in contact with the skin and ingestion of any and all parts: leaves, fruits, stems, roots.
If you find belladonna in your garden, you need protection to remove it.
Wear long sleeves, long trousers, closed shoes, gloves and a respirator to avoid skin contact. You can also wear glasses.
You need to dig up the plant with its root system to prevent the belladonna from growing back.
Then safely dispose of the plant.
Then you need to disinfect the tools with which you dug belladonna: secateurs, a shovel.
Use chlorine bleach to disinfect. For 1 cup of chlorine bleach, add 1 gallon of water.
When cleaning, be sure to use gloves that will not let water through. Dispose of the solution as well.
After that, you need to wash your work clothes separately from other things.
You can also use a chemical called herbicide to remove the plant.
Apply the product when the shoots are still small.