We’ve said it before: Don’t put cotton swabs in your ear to clean out the wax.

In case you weren’t convinced, consider this: from 1990 to 2010, there were more than 263,000 emergency room visits in the US for ear-cleaning injuries in children. That translates to about 34 visits per day.

Researchers from the Nationwide Children’s Hospital in Ohio analyzed data from the National Electronic Injury Surveillance System on emergency department visits at 100 hospitals across the country. Hospitals use different codes to indicate why patients make the trip; the researchers looked at all of the codes for ear injuries in children involving cotton swabs, cotton-tipped swabs, or Q-tips (the common name-brand cotton swab that, ironically, specifically warns against sticking them into your ear.) They then scaled up their findings to estimate numbers for over 5,300 hospitals to represent the entire country, and published their work in the Journal of Pediatrics on May 1.

The most common cotton-swab ear injury that brought patients to the emergency room was ear bleeding, often caused by ruptured ear drums. The second-biggest complaint was foreign object syndrome, a condition in which it feels like there’s something stuck in an orifice (it’s not limited to ears). Two-year-olds had the most cotton swab-related ear injuries, and the number of visits for these injuries in general declined as kids grew up.

Almost three quarters of these injuries were failed attempts at ear cleaning. Most of the times, kids hurt themselves trying to clean their own ears, but parents or guardians were also often guilty of causing ear injuries. (So were siblings about 7% of the time.)

But ear cleaning shouldn’t be a part of anyone’s hygiene regime. “The ears’ canals are usually self-cleaning. Using cotton tip applicators to clean the ear canal not only pushes wax closer to the ear drum,” Kris Jatana, a physician at the Nationwide Children’s Hospital and lead author of the study, said in a statement.

On the bright side, there were fewer injuries over time; the researchers estimate that in 2001, there were about 17,500 emergency room visits per year and in 2010 there were about 12,900. There isn’t more data from recent years because the National Electronic Injury Surveillance System stopped coding for cotton swab injuries, making them harder to track. Maybe the organization wishfully thought people would finally stop putting Q-tips in places where they don’t belong.