You can pack liquids in a bento box, but it's essential to choose the right container and take precautions to prevent leaks or spills. Here are some guidelines for packing liquids in a bento box:

1. Use Leak-Proof Containers: When packing liquids like soups, sauces, dressings, or yogurt, use leak-proof containers or small sauce containers with secure lids. This will prevent the liquids from leaking into other compartments or the outer bag.

2. Silicone Cups or Dividers: Consider using silicone cups or dividers inside the bento box compartments to hold liquids securely. These cups are often leak-proof and provide a separate space for containing liquid items.

3. Position the Bento Box Properly: If the bento box has multiple compartments, place the liquid-containing containers in an upright position to minimize the risk of leakage.

4. Avoid Overfilling: Leave some empty space at the top of the liquid containers to allow for expansion and prevent spillage when closing the lid.

5. Thickening Agents: For soups or sauces, you can use thickening agents like cornstarch or arrowroot to make the liquid less runny and reduce the chance of leaking.

6. Keep the Bento Box Upright: During transportation, keep the bento box upright to minimize the movement of liquids inside the containers.

7. Double Check for Leaks: Before placing the bento box in a bag or lunch tote, double-check for any leaks by gently tilting the containers.

8. Use Sealed Bags: If you're still concerned about potential leaks, consider placing liquid-containing containers in a separate sealed plastic bag before placing them in the bento box.

9. Choose the Right Bento Box: Some bento boxes are specifically designed with leak-proof compartments, making them more suitable for carrying liquids.

Remember that even with proper precautions, it's always best to avoid packing extremely runny or overly liquidy items in a bento box if possible. Opt for thicker or less liquidy foods to minimize the risk of spills and ensure a mess-free lunch experience.