you could be seeing interference with the wireless unit. Secondly, optical mice are very sensitive to the material upon which they sit: are you using an optical mousepad or other surface that is optical friendly? It could be as simple as you needing new batteries in the unit since it’s wireless. There are plenty of reasons that your cursor could be weirding out, actually.
If your actual mouse unit is jumping then I think you might want to vacate your house or get a really aggressive cat or something. I presume that you mean that the cursor on your screen leaps around.