What are the grey bugs attracted to water multi legged roll into a ball when touched?
<quote> It's called a roly-poly. <quote>
Actually, it's called a pillbug or, the scientific name, is Armadillidiidae and it's in the family of woodlice. Because they roll into a ball when threatened many have called them roly-polies or potato bugs. However, it's a common mistake as these are not bugs at all but they're actually crustacean much like shrimp.
Why would a stream of water be attracted to a charged plastic rod but a stream of carbon tetrachloride not be attracted?
The charged rod attracts water because water is polar; the electrostatic charge pulls the opposite charge of the water molecule towards it. This happens regardless of the charge on the rod, because the water has both charges. Carbon tetrachloride is nonpolar, however, and so there is nothing to be attracted to the rod.