Only the grubs are affected, leaving beneficial organisms unharmed. Milky spore multiplies over time and will sit inactive, waiting for grubs to infect. The grubs are actually the larvae of Japanese beetles.
Most yards have grassy areas that homeowners only set foot on for weekly mowing that might be put to more productive use capturing rainwater, storing carbon, or even growing food. A mixed planting of berry bushes and native flowers, for example, can provide food for your family and endangered pollinators. For lawn grubs, there is a natural remedy called milky spore. The granules are spread on the soil and cause the grubs to contract a disease that kills them.
Roll it following installation to ensure contact with existing soil and keep it well watered until established. If there are areas in your yard that never get used for recreation, consider replacing them with perennial plants or trees that are more environmentally beneficial.