There many conditions that encourage the breeding of pests and parasites. The most common condition is a dump place and also a place that is usually dirty.
Conditions that encourage the breeding of pests and parasites include warm temperatures, high humidity, presence of food sources, and access to standing water. Cluttered and unclean environments also provide breeding grounds for pests and parasites to thrive. Proper sanitation, regular cleaning, and maintenance can help prevent their breeding.
Depends what you mean by "unsafe", medically speaking they can stir up alot of allergies etc
Stagnant water
By shoving it up your but, thats how!
in clean places
You shouldn't. Leave 'em alone.
Fungal issues and mosquito breeding.
they come from egg sacks.
Conditions that encourage the breeding of pests include the availability of food sources, water, and shelter. Additionally, warm temperatures and favorable humidity levels can also contribute to pest breeding. Poor sanitation and cluttered environments can further facilitate pest infestations.
Pest Control
water,stagnant water and food that is not covered.