Rabbit does may urinate on their kits for several reasons, though it is not a common behavior and usually happens accidentally. Here are a few possible explanations:

1. Scent marking: Rabbits have scent glands located near their genital area, and they may release urine to mark their territory. Sometimes, a doe may accidentally release urine while tending to her kits, and this can happen when she is in a heightened state of arousal or stress.

2. Stress or fear: If a doe feels stressed or threatened, she may urinate as a defensive mechanism. This can occur if she feels her nest or kits are in danger or if she perceives a threat in her environment.

3. Poor nest box design: If the nest box is not designed properly or is too small, the doe may accidentally urinate on her kits while attempting to nurse or care for them. It is important to provide a spacious and well-designed nest box to minimize the risk of this happening.

4. Inexperienced doe: Sometimes, a first-time mother may exhibit accidental urination on her kits due to inexperience or confusion. As she becomes more experienced with subsequent litters, this behavior may decrease or disappear.

If you observe a doe urinating on her kits, it is important to monitor the situation closely. Ensure that the kits remain clean and dry to prevent any potential health issues. If the behavior continues or if you have concerns about the well-being of the kits, it is best to consult a veterinarian or an experienced rabbit breeder for guidance. They can provide specific advice based on the individual circumstances and help ensure the health and safety of the kits.