These mites with their anus on your face are doing you a favor


  • The mites are about 0.3mm long and are found in hair follicles on the face and nipples, including the eyelids and eyelashes.
  • They have many more cells at a young age compared to their adult stage.

They are invisible to the naked eye. Microscopic mites, called “Demodex”, are constantly present on our skin. These little beasts, which become more numerous in adults as the pores enlarge, were passed on to us at birth. “Follicular mites are the only metazoans that live continuously on the epidermis of human beings”, said researchers from Bangor University in Wales. Those found on the face are called “Demodex folliculorum”.

Active mites at night

In a recent study published in the journal Molecular Biology and Evolution, scientists have analyzed the DNA of these mites for the first time to learn more about their secret lives, specifically about their body characteristics and their evolutionary future. For the purposes of their work, they used the sequencing of the genome of “Demodex folliculorum”.

According to the team, these tiny beasts, which colonize the pores of the skin, mate on our faces while we sleep. To do this, they move between the hair follicles. According to the results, these mites feed on the sebum naturally released by the cells in the pores. Simply put, they help our pores open up and remove oils that contribute to blemishes and infections.

The authors revealed that the existence of these mites was isolated. “We found that these mites behave very differently from parasites. We found that these mites have a different arrangement of body part genes than similar species because of their adaptation to a sheltered life inside pores. These changes in their DNA resulted in bodily characteristics and behaviors.” said Alejandra Perotti, a professor who co-directed the research, in a declaration.

Endangered due to genetic loss

Genome sequencing revealed that the permanent association of “Demodex folliculorum” with its host resulted in a genetic reduction. Clearly, this decline is due to their isolated existence, lack of exposure to external threats, and encounters with other mites with different genes. This genetic reduction would cause the mites to become organisms “simplified” and soon they could become one with human beings.

This genetic loss is also the cause of their nocturnal behavior. Dust mites have no UV protection and have lost the gene that allows them to wake up in daylight. The unique arrangement of their genes is also responsible for their unusual mating habits. His reproductive organs advanced.

Dust mites are not the cause of skin diseases.

For a long time, some researchers assumed that mites did not have anus and that they must accumulate all their feces throughout their lives before releasing it when they died, causing inflammation of the skin. But this recent work has confirmed that these little beasts do have anus, and have therefore been unfairly accused of being responsible for many skin conditions.

“Mites have been blamed for many things. Their long association with humans could suggest that they may also have simple but important beneficial functions, for example keeping facial pores unclogged.” concluded Henk Braig, co-senior author of the study.

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