Here's why:
* Not enough warmth: Hay and grass lack the necessary insulation to keep baby rabbits warm. They need something fluffier and more insulating like soft, shredded paper, or a commercially available nesting material.
* Lack of protection: Hay and grass can be too coarse and sharp for delicate baby rabbits.
* Limited nesting instinct: Hay and grass might not trigger the rabbit's instinct to build a proper nest.
What to do:
* Provide a nest box: A dedicated nest box with a smooth bottom is essential. It should be large enough for the mother to comfortably stretch out, and have a solid side so she feels safe.
* Offer appropriate nesting material: Provide a good amount of soft, shredded paper, or a commercially available nesting material specifically designed for rabbits. You can also try offering fleece strips or cotton batting, but ensure they are free from any potentially dangerous chemicals.
* Observe the rabbit: Watch your rabbit carefully to see if she's building a nest. If she's not, try offering her some nesting material directly in the box.
* Consult a vet: If you have any concerns or doubts, consult your veterinarian. They can offer specific advice and guidance for your rabbit's needs.
Remember, a safe and comfortable nest is crucial for the well-being of both the mother and the babies.