Moon's disadvantages?

<<it gravity affects volcano eruption>>

Not true. The only thing that the moon's gravity affects are the tides in the ocean. it has no effect on volcanoes, earthquakes or how much anyone weighs

I don't know a great deal about the moon but I suppose it does block of the suns light, (in a solar eclipse,) which technically is a disadvantage. You could say that the moons makes the sky glow, making it hard for astronomers to see stars etc. (This has been said in another comment.)

If anything the moon is very useful. It can act as shield, it helps wildlife navigate in the dark and birds migrate according to it?

Hope I've helped. =)

Well, astronomers are never happy with it because it makes the sky glow, and makes it harder to see stars... I can't think of any other 'disadvantages.'

I agree with quantum... The moonlight is so bright that you sometimes can't see dim stars around it.

Your question is very vague and confusing...you should reword it.