Getting rid of an intrusive cat

Question
A young small cat sneaks into our basement and utility room each day and is most unwanted. We've tried blocking up each possible entry-way, but have been unsuccessful. Is there a spray or other material that a cat would find so distasteful as to not come back?
We certainly need help with this problem. Many thanks.
Stanfree

Answer
Hi
cats don't like strong smelling citrus smells so using a strong citrus spray (lemon and water will also work) around doors ways etc may help to dissuade them from coming in. there are also some cat repellent sprays on the market but i have not tried them myself and so cannot say how good they are.

I wonder how she is getting if you have blocked all the doorways etc? Finding her entry point and clocking that will be the ultimate problem solver or course but you know that already.
Apart from these suggestions i cannot think of what else to suggest. Sorry

Kate