In northern Europe, the fly often lays its eggs in sheep wool. The larvae then migrate down the wool where they feed directly on the skin surface in a process called myiasis. This can cause massive lesions and secondary bacterial infections, causing serious problems for sheep farmers. In the UK, blowfly strike affects an estimated 1 million sheep, as well as 80% of sheep farms each year. This causes a huge economic impact in regions affected by blowfly strike. Not only does it cost money to treat infected animals, but measures also must be taken to control "L. sericata."