I was sitting on my bed and noticed what looked like a slug, i asked my husband to confirm what was on top of our bed. indeed it was. we live in Iowa.

How is it or is it possible to find a slug on top of our bedding, and why there? This is the first time one has been noticed. Can they attach themselves to articles of clothing and not be noticed, and fall off where ever you are sitting or laying articles of clothing on beds, or any other types of materials?

If you find one does this mean there is more to watch for and find in our home?

Difficult to say much without a picture and identification of what the animal was. If you are asking could a slug climb onto a bed or up a wall and then land on the bed  - yes probably.