Figure 8.

Representative still frames illustrating specialized grip configurations and independent digit movements in rodents during food handling. (A,B) A rat eating uncooked spaghetti, the left hand holds the pasta near the mouth with the digit tips (a modified precision grip) while the right hand uses a scissor grip between digits 4 and 5 to push the pasta toward the mouth. (C,D) A hamster eating a sunflower seed, both hands hold the seed in a modified precision grip between digit 1 (the thumb) and digits 2 and 3 as the mouth bites into the shell. Two objects can also be held at once, the seed is held in a modified (bilateral) pincer grip between digits 1 and 2, the shell is held in a bilateral power grip between the palm and digits 3 and 4, while digit 5 is positioned on the ventral surface of the seed, likely to stabilize the grip on both objects. (E,F) A Mongolian gerbil eating a sunflower seed. A bite from the incisors is used to open the shell (not shown). The bottom half of the shell is held in the digit tips as the left hand uses a precision grip to grasp and discard the top portion of the shell. The left hand then grasps the bottom half of the shell in the digit tips (precision grip) and discards it as the right hand uses a precision grip to hold the seed in the mouth. Adapted from Whishaw et al. (93), Whishaw et al. (92).