Some questions about mice

Today I went out and bought a 3:2 pair of albino lab mice.

I have no experience keeping mice and dont know anything about their behaviorism.

When I put them in their new tank they immediately went to the food bowl and started kicking a bunch of it out, as if they were going to to lay down in it(they seemed to do this at the store I got them from), is this normal for mice?

At what weight is it ok to start attempting to breed at? I weighted one and it was 30grams.

Any other tips/suggestions for caring for my snakes next meals would be much appreciated.

I will suggest this, making a hopper to hold the food so it's not wasted.

Like this
http://www.ball-pythons.net/forums/s...ad.php?t=66110

Or like this
http://www.ball-pythons.net/forums/s...?postid=824120

Or you could make a short rack for them like this
http://www.ball-pythons.net/forums/s...ad.php?t=65939

Lots of different shapes and sizes. I use a lab block to feed my rats but I have never kept mice.