Collisions work like this:
Imagine the bots are giant mashmallows. You can squeeze two marshmallows into the same space, but if you let go they'll unsqueeze and push apart. That's what the bots are doing. It's like each bot is a damped spring. Their collisions are quite "soft".
Mutation of Mutation rates are called Delta Mutations. (Delta after the greek letter that looks like a triangle, and is used in physics as notation for "change in".)
The 95% things require some basic understanding of statistics. Lots of data falls onto a bell shaped cuve. 95% of that data generally falls between 2 standard deviations from the mean (average).
Thus for length, if you had a mean of 5 and a standard deviation of 1, 95% of generated length values will be between 3 and 7, with more values clumping towards the 5 and less towards the 3 and 7.
A std dev of 0 produces all identical values around the mean.
Are you sure it's not that you need to buy a computer with mroe RAM? How much RAM are you running, anyway? When the env grid is added, it will take another 20 megs atleast. This is nothing on new computers, but if you're running a 486 with 40 megs of RAM...
I think I forgot to change ties to snap when they get too long.