Bleeding is a sign that your gums have been irritated for a while, most likely from dental plaque, loose or erupting teeth.
If you notice localized traces of bleeding in the mouthpiece of your child after use, you shouldn't be worried. Willo, or any other toothbrushing device, when used in normal conditions, is not known to cause gum trauma and bleeding is primarily a sign of some gum inflammation.
Since using Willo involves a more dynamic gum massage, inflamed or sensitive gums may take a few days to adjust to this new method. We recommend you to choose the softer cycle on the Willo app for your kid to start with. To change the brushing cycle, consult this article.
If they persist after 10 days, please contact us at support@willo.com or talk to your dentist.