You should remove brown balls in the garden as quickly as possible. In autumn, the female ticks look for a suitable spot and lay around 2,000 eggs there.
The pile of small pellets lies there over the winter until spring until the tiny larvae hatch. Since these develop into disease-carrying bloodsuckers that you don't want in your garden, you should keep your eyes open for the nests. The most common tick species in Germany is the common wood tick (Ixodes ricinus), not to be confused with the bark beetle that lives in the bark.