riddle - Word of the Day #2

Test run, take two. The first run went well, so let's keep it up!

For your second riddle, things might just get trickier -
With some common bond, things might just get stickier!
When I'm with a group I'll be holding you tight;
When alone, I'll protect you in the absence of light.

What am I?

Answer

I'm not too sure, but I'll guess:

Rubber

With some common bond, things might just get stickier!

Rubber cement (a type of adhesive)

When I'm with a group I'll be holding you tight;

Rubber band (group = band)

When alone, I'll protect you in the absence of light.

Rubber (i.e. condom, "protection" at night time, alone = no other word)