Mountain biking at night without lights can be very challenging and potentially dangerous. Here are some tips to help you attempt this activity safely: 1. **Ride when there is plenty of moonlight**: Choose a night with bright moonlight, such as a full moon, to improve visibility. 2. **Know the route**: Choose a route you are very familiar with so that you can anticipate road conditions and know potential obstacles and terrain changes. 3. **Ride slowly**: Reduce your speed so that you can better react and handle unexpected situations that may arise. 4. **Use night vision goggles or equipment whenever possible, which can enhance your vision without lights. 5. **Keep it quiet**: By reducing noise, you can better hear the sounds of your surroundings and help identify changes in road conditions or potential hazards. 6. **Ride with other experienced riders**: Go with other experienced riders who can provide support and help. 7. **Enhance other senses**: Focus on enhancing non-visual senses, such as hearing and touch, to perceive changes in your surroundings. Please carefully assess the risks and difficulties of this activity and plan carefully to ensure safety. Especially in the absence of any light source, riding at night may put you and others at unnecessary risk and must be done with extreme caution.