Per the link below, it says, ". For improved drainage add grit or sand (sharp sand, not builders sand, which compacts)."

and
* Add a handful of sharp grit to the holes when planting tulips and other bulbs to prevent voles from tunneling up.

Sue

Here is a link that might be useful: Solutions to Common Problems in Your Garden:

Thanks for the link Sue. I read on there that voles hate daffodils so I will be planting plenty of them too. Judy

You're welcome.

I read on there that voles hate daffodils so I will be planting plenty of them too.
YAY!

Sue