If the worst thing the child does is rip up some grass, you got a "good one".
Red Sovine sang a song about just this once-"It'll come back"
http://www.youtube.com/watch?v=lNxlRnFoyfM
You say the kid is 2-1/2....not knowing what climate/region of the country you're in, it may be that the kid hasn't seen grass since last summer, which would have been about 20-24 months old.
If you think what he's doing to the lawn is bad, leave the kid in a room with a kitten for 30 mins and come back and see what's left-kids are animals, it's our duty to teach them to be civil human beings.