tap them of course! keeps space open for more. do you want more goo or not, 2 goos each while friends are awake all day long ain't bad at all, placing gremlins in towns where your friend lives on other side of the planet more then likely will give you all four cause there sleeping, friends on the other side of the world placing gremlins in your town while you're sleeping, same thing, they get all 4, so it works out in the end. Definitely tap them when ya see them. i'm getting over a 1000 goo a day. 275 goo from 8000 as of this writing