The phrase "natural flea" refers to a flea that occurs in nature rather than being artificially created or modified. It usually implies that the flea exists without any human intervention or manipulation. Full definition
A clean environment is particularly important for natural flea control in warmer months or if you live in a warm climate, as this is when the flea life cycle is more rapid. (myhealthycat.com)
Like a number of natural flea products this item uses the power of plant extracts, which are non-toxic and safe for your family and pets. (dachshund-owner-guide.com)
As for natural flea remedies, I make for her at home anti itchy remedies but have not tried for fleas and am a little confused on this one. (fidoseofreality.com)