Re: I need help finding a Science Project Topic .

Some ideas:

food preference--you might compare foods that rabbits would 
normally eat in the wild (grasses and other plants in your lawn) with 
foods rabbits only get in captivity (rabbit chow, or exotic things like 
fruits or vegetables that don't normally grow in your area); OR you 
might compare different types of common vegetables (even different 
types of lettuce) that have different nutritional contents to see if the 
rabbits prefer more nutritious foods (you could focus on the amount 
of fat in the different foods, or vitamins, or calories, or almost 
anything--all this information is available in nutritional tables in 
books)

habitat preference--you might compare different types of nest boxes; 
for example, ones made of different types of materials (wood versus 
plastic) OR ones containing different types of bedding (wood 
shavings versus cloth or straw or no bedding at all)

learning--you could try training the rabbits (using a food reward) to do 
certain tasks like running a simple maze, or going through an 
"obstacle course" in a set pattern (for example, around the coffee can 
to the left, over the pile of books and through the hole in the 
cardboard box); you could compare different rabbits based on 
their sex or age (for example, do females or younger rabbits learn 
faster or remember longer than males?).

Good luck!