I hope you mean the 2009 season, because wood frogs have long since bred, laid eggs, and the tadpoles have morphed by now in most areas so you're out of luck there. You could also look for them yourself - talk to some nature centers in the area, ask if they have any vernal pools and for permission to take students there. You could also visit some state forest land , driving around on your own and scouting the area first. Taking a field trip to a vernal pool in mid-March would be a great experience for any 2nd graders.

Next, while its long been done, it really isn't wise to release animals back into the wild that have been in captivity with the gamut of diseases that are affecting amphibians nowadays. If you have no other herps in your classroom, it'd probably be alright; however if you have any other amphibians I wouldn't risk it.

If you'd like any assistance with this in the future, please feel free to email me at mpgraziano AT gmail DOT com.
~Mike

I copied this as it was easier than typing it out. It applies to Ohio but should be good for Illinois as well.
"The woodfrog is an example of an explosive breeder, a species that congregates in large numbers at breeding ponds for a very short mating season lasting only two or three days to a week. They become active in mid-March and remain so until late October. Spawning is accomplished in small temporary pools, swamps, or semipermanent ponds and takes place from mid-March to early April in northeastern Ohio. Woodfrogs often lay their clutches of eggs aggregated in a central location of the pond thereby forming huge rafts of eggs deposited below the surface of the water. Individual egg masses are globular in shape and measure 75-100 mm in diameter. Each mass may contain 1000-5000 eggs with each egg swelling to 6-7 mm in diameter upon hydration. The eggs hatch in 14-21 days, and transformation occurs 61-115 days following spawning. Woodfrog tadpoles are dark, nearly black, and transform the year they hatch at lengths of 38-48 mm. Recently transformed woodfrogs 15-18 mm in length may be found from early June through late July. Sexual maturity is reached in two years."

Here is a link that might be useful: Frogpatch Where kids and adults learn nature

I don't think taking wild animals from the wild and keeping them in a classroom promotes ecological awareness. It teaches them that it's ok to take wildlife out of the wild. And it's not OK. It's interference, cruel and often illegal.

Also: Many tadpoles rely on the food provided in their natural environment. So getting stuff at Petsmart, besides not teaching ecology, is not good for them.

More educational would be looking for vernal pools in the spring/summer to see where frogs begin. Most if not all frogs rely on vernal pools to breed. Teach the kids about ecology by taking them into nature.

The MO conservation dept. has a pamphlet on how to raise tadpoles for teachers so they must think it is OK.

Here is a link that might be useful: tadpoles

Conservation departments are in charge of hunting.

Find a teaching organization that thinks it's a good idea. Thenn come back and show me.