They can be some type of viral agent in which case these viruses will infect our cells. And what these neutrophils can do is actually engulf those cells that have been infected by our virus. Now, what about basophils? Well, basophilus and eosinophilus are found in high concentration if the invading pathogen is some type of allergen or some type of parasite. So these respond to infections due to parasite or allergic reactions. They move from the blood and into our tissue and also release histamine.