Im not trying to raise monsters here.. but my boys seem to be growing extremely fast

My spider has greatly slowed down in the past month or so, while my normal is getting to be a fatty!

Right now...depending on the mood of the snake - Im doing 3 mice every 7 days or if they are nice.. a small medium rat every 7 days.

Their growth in the past 4 months -

Spider:
Got him on 3-15-10 -
First weighing on 3-22-10: 217g
As of today - 7-12-10: 596g
Gaining: 379g in 4 months.

Normal:
Got him on Jan 15thish
Weigh in on 2-15: 133g
Same Weight in as Spider 3-22-10: 172g
As of today - 7-12-10: 605g
Gaining 433g in 4 months.

At what point so we say - ok - you are gaining really well - now lets slow this down a little and move to feeding every 2 weeks or so - or is there really no time limit and you stop feeding every 5-7 days when they start refusing food.