Nico Doornenbal, of Waimairi Primary School, asks :-

Can an ant be made much bigger?

Tony Signal, a biophysicist at Massey University, responded.

It is very unlikely that an ant could be made two or three times bigger than its normal size.

If an ant were scaled to double its size (a 'doublant') not all of the ant's characteristics will change by the same amount. For example, doublant's muscles and bones will be about four times as strong as before but its weight will be about eight times larger than before.

This means that there is twice as much pressure on its legs as before, and so it will be very easy for one of the legs to break if the doublant has some unexpected stress, like jumping or landing. Also it will be very exhausting for the doublant to walk very far. This is similar to what would happen to you if instead of walking, you decided to hop everywhere on just one leg. You would get tired very easily and you would have a lot of trouble doing things like climbing stairs or landing safely if you had to jump off a bench.

The doublant wouldn't be able to 'breathe' properly. Ants, and other insects, don't have lungs like we do. Instead oxygen is transported throughout their bodies through small tubes (trachea) from small holes (spiracles) all over their bodies. Because it is about eight times as heavy as a normal ant, it needs about eight times as much oxygen, however the holes and tubes can only supply half of that need. So the doublant will always feel as if it has just run a long race, and would much prefer to rest rather than go and look for the food it needs.

So in the end our doublant will have a rather poor life. It would always feel tired, be unable to run, and it would be very likely to break one of its legs and hence be unable to run away if some predator discovered it.