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# Magic Caterpillars

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Age 14 to 18

Challenge Level

In the Land of Trees all the caterpillars have numbers on their feet and hips (vertices) and on their legs and body segments (edges) as shown on this 4 legged caterpillar. All the whole numbers from 1 to $v+e$ are used where $v$ is the number of vertices and $e$ is the number of edges. Biologists classify them by their vertex-sums.

A vertex sum is the total of the numbers on the vertex and all the edges at that vertex.

The caterpillar shown has vertex sums:

11 (8+3), 13 (9+4), 15 (10+5), 17 (11+6), 25 (8+9+7+1) and 30 (7+10+11+2).

Show that one day a biologist may find a rare magic 4-legged caterpillar having the same sum at all its vertices and describe this creature.

Could there be two species of magic 4-legged caterpillars with different numberings?

Do magic 6-legged caterpillars exist?

What about magic caterpillars with even more legs?