The answer to 'why is my tick nests' is that you likely have a tick infestation in your home or yard. Ticks can build nests in areas with tall grass, leaf litter, or other overgrown vegetation where they can easily find hosts like pets or people to feed on. Signs of a tick nest include the presence of ticks, tick eggs, or tick larvae in these areas.
To address a tick nest, you'll need to thoroughly clean and remove the nesting materials, then treat the area with an EPA-approved insecticide or acaricide to kill any remaining ticks. This may be a difficult and time-consuming process, so it's often best to call in a professional pest control technician who can properly identify the tick species and use the most effective treatments to eliminate the infestation.