Can't find dropped pill..i'm a wreck.?

My mom is 81..she accidentally dropped a baby aspirin on the floor this morning..i saw it fall ..watched it hit the floor but couldn't find it....I have 6 cats and i am a nervous wreck that they will find it and eat it...i spent the ENTIRE day sweeping..vacuuming and mopping that section of the house...i can't find the damn pill...i looked through the vacuum dirt to see if i picked it up but it wasn't there...i just don't know what else to do...i lifted the area rugs..moved furniture..cleaned everything...the pill just can't be found..i know it fell...i just am afraid that one of the cats will find it...i'm a nervous wreck but can't find a solution to this.