Yes, some rabbit owners use diatomaceous earth (DE) as a preventative measure or for pest control in their rabbitry. DE is a natural substance made from fossilized remains of aquatic organisms called diatoms. It comes in a powdered form and is often used for its insecticidal properties.

Here are a few ways in which DE may be used in rabbit care:

1. Pest control: DE is known for its ability to control pests like fleas, ticks, and mites. It works by absorbing the protective waxy layer of insects, causing them to dehydrate and die. Some rabbit owners may use DE to help control external parasites in their rabbits' living spaces.

2. Environmental treatment: DE can be used to treat the rabbitry environment for pests. It can be dusted in areas where pests are present or suspected, such as bedding, corners, and cracks. However, it's important to apply DE sparingly and avoid excessive dusting, as inhalation of the fine powder can be harmful to both rabbits and humans.

3. Prevention of dampness and odor: DE has absorbent properties, and some rabbit owners use it to help control moisture and odors in rabbit enclosures. Applying a thin layer of DE on the floor of the enclosure or in litter trays may help absorb excess moisture and reduce odors.

When using DE with rabbits, it's important to follow safety precautions:

- Choose food-grade DE: Ensure that you use food-grade DE, which is considered safe for use around animals and humans. Avoid using DE products that contain additional chemicals or additives.

- Minimize dust exposure: DE is a fine powder, and inhalation of the dust can be harmful. When applying DE, take care to minimize dust clouds and avoid direct exposure to rabbits and yourself. Consider wearing a protective mask to reduce inhalation.

- Use sparingly: Apply DE in moderation and avoid excessive dusting. It's important to strike a balance between pest control and preventing unnecessary exposure to the rabbits.

While DE may have some benefits, it's always a good idea to consult with a veterinarian before using any products for pest control or preventative care in your rabbitry. They can provide guidance specific to your rabbits' needs and help ensure the safety and well-being of your rabbits.