How large are the locusts with tails like scorpions, with stings in their tails?

Revelation 9:3 And there came out of the smoke locusts upon the earth: and unto them was given power, as the scorpions of the earth have power.

  5 And to them it was given that they should not kill them, but that they should be tormented five months: and their torment was as the torment of a scorpion, when he striketh a man.

  10 And they had tails like unto scorpions, and there were stings in their tails: and their power was to hurt men five months.

Are they about the same size as locusts which eat grass and herbs?

Will there be as many of them as the number of grass and herb eating locusts, that are, at this time, swarming Africa and the Middle East?

There are many billions of the grass and herb eating locusts, today.

Could there end up to be a similar number of the locusts with scorpion sting tails?

I have always heard that the locusts with the scorpion sting tails will be world wide,

but are not the current swarms of herb and grass eating locusts in mostly islamic nations?

Why would the locusts with scorpion sting tails have to be in every nation of the world?

Will it be like one sting per person?

Or will it be many stings per person, all day long, every day, for five months?

Will they be able to follow people into their houses or into their cars?

Will there be any hiding from them?

The thought of this terrified me, the first time I read the book of Revelation, and that was before the gosepel came to me.

Revelation 9:6 And in those days shall men seek death, and shall not find it; and shall desire to die, and death shall flee from them.

I wonder, how bad could this be?

Could it be like a man, trying to escape the stings, jumping off a tall building, to kill himself, only to not be able to die?

In that case, would the man end up laying on the ground, writhing in great agony,

but unable to move away because his bones are broken,

only to be then covered by a swarm of locusts with scorpion sting tails,

to relentlessly sting his already agonizing body?

Should we not be warning people of the horrible things to come on the earth, then later in hell, and finally in the lake of fire,

that they will sadly have to face if they do not repent to believe the gospel?

If we believe the following:

Acts 16:30 And brought them out, and said, Sirs, what must I do to be saved?

  :31 And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house.

Then why are we not as desperate in bringing them the gospel, as they will be running from the locusts with scorpion stings?