Yes you can. I'm currently doing that.
But before you buy the board you may wanna figure out how many DC motors, servos and sensors you'll need, and do some research on these.
A standard Arduino board (eg. Duemilanove) can control up to 12 servos. I'm not sure how many DC motors..I suppose 6 since that is the number of socalled PWM (pulse width modulation) outputs on the board.
And it isn't necesary to buy an additional motor/servo shield allthough that may make things easier for you. If you're planning to use a LOT of servos buying the RoboDuino board (instead of a Duemilanove) is another option that will make things easier for you (without buying an additional shield).
Here it is:http://www.curiousinventor.com/kits/roboduino
I don't know what "larvals" mean, but I suppose you mean tracks?! If so they are typically moved by 2 DC motors.
Note: Many people use modified servos as DC motors since they're easier to deal with. There are lots of manuals on the web on how to do this modification.
Here is a link to a topic I posted on this forum that may be of use if you wanna use a lot of servos:http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1251519060