The multiverse theory is based on the assumption that the creation of a universe is a naturally occuring thing. Therefore it should be happening all the time in different places. The theory also suggests that the universes cluster together into multiverses the same way stars and planets form galaxies. (Just so you know.)

About your example of ants in a plastic container;
I think you're implying that somewhere there is a set of rules different to our's which particles follow. (or there are different rules in many different places.) Let us look at numbers. there are many different rules numbers can follow. for example, you can keep multiplying a number by 2. the rule here is simple, and it is easy to predict what will happen in the future. Prime numbers also follow a set of rules, they just have not been found yet. My point is, numbers can have an infinite set of rules to follow. But these rules will all be based on simple, basic rules. For example, you can't add 1 to 2 and get anything other than 3. that is what i meant by 'golden laws'. So, to be able to create a set of new, working laws, something would already have to be there to create them. no matter which set of laws this 'something' came from, it too would be a product of the golden laws.

You said that you agreed that something can't be created of of nothing. Yet, you also said you do not know how i could possibly know that everything needs mass to exist. Well, let's use the example of numbers again. To get from 1 to Zero you would have to pass through an infinite amount of numbers.
e.g. 0.0(recurring)9871. With this in mind, it is impossible to ever get to zero. That is why I don't believe that there is anything without mass.
(by the way, the numbers were a representation for particles)