Rats gnaw constantly to keep their teeth from growing too long, so the materials they encounter in their environment directly shape what they chew. You place six wire types in a cage with three hungry rats — ranging from thin telephone wire to thick power cable — and leave them for 24 hours. Then you inspect each wire for bite marks. Next, you repeat the test with live current running through the wires. The rats chewed telephone and PVC wires both with and without current. They ignored the thicker cables entirely.

Squirrels leap between tree branches without a second thought, but exactly how far can they go when food is the motivation? You set up two tables 300 mm apart and place sunflower seeds on the far table. A PVC pipe on the near table guides each squirrel to the edge. After each successful round, you increase the gap by 300 mm. A soft cushion below catches any missed jumps. The squirrels cleared distances of 1 to 1.5 meters. The farthest successful jump reached 1.5 meters — showing how far rodents push their physical abilities to search for food.