Sometimes there’s just an itch you just can’t scratch, and sometimes it’s more than just a bad case of the itches. An unidentified 7-year-old girl must have done a lot of head scratching after having what is possibly known as the worst case of pediculosis capitis, also known as head lice. A YouTube video uploaded by user guallan, captures the child’s mother running a fine-toothed nit comb through her daughter’s coarse hair, which appears to be filled with hundreds of crawling parasites.

“Look at how the lice comes out. It keeps piling up in the comb,” says the mom in Spanish in the video. Head lice commonly affects children and is the result from the direct transfer of lice from the hair of one person to the hair of another, says the Mayo Clinic. This isn’t a sign of poor personal hygiene or an unclean living environment.

The accumulation of lice on the scalp is the result of the female laying her eggs close to the root of the hair so they are kept warm by the scalp. The female only needs to lay once and lives for 30 days, laying up to 10 eggs a day. These eggs hatch into more lice, which breed and multiply. The lice bites into the scalp and feeds on the blood to survive.

Ian Burgess, director of the Medical Entomology Centre, in England, told the Daily Mail: “There must be 200 to 300 adults there. However, the combing technique is odd, without any break or cleaning of the comb. Strangely, the lice all seem to be stuck to the middle of the comb, but I cannot work out why or how. This kid would have caught lice in the normal way, and then the numbers just grew unchecked because nobody did anything.”

Based on the accumulation of the lice in the video, Burgess suspects it started a few months ago. Head lice can often go undetected if not diagnosed correctly, since they are one-third the size of a sesame seed and take a week to hatch. Also, not everyone is allergic to lice, which can lead to the lack of itchiness. If someone with head lice is allergic, it can take up to three months to develop itching.

A person who has been infested is required to use an over-the-counter product or prescription medication. According to the Centers for Disease Control and Prevention (CDC), patients should comb away dead lice and any remaining live lice out of the hair using a fine-toothed nit comb. Patients should check every two to three days to decrease the chance of self-reinfestation.

The mother was not properly adhering to the directions by not cleaning her comb after combing through her daughter’s hair. This means the lice will drop back into the hair and onto the floor and seat, increasing the likelihood she will get infected too. Moreover, the girl’s hair wasn’t wet enough, tearing the girl’s hair out.

When treating head lice follow the suggested precautionary steps on the CDC’s website to prevent further infestation.