From Fantastic Wiki
A snake is a contraption technique constructed by layering many water rods on top of each other, but all connected to the same joint. When this joint is put into motion, some seemingly strange effects ensue. The snake will appear to have anti-gravity properties and behave quite unpredictably.
The reason for this is that the snake takes advantage of the elasticity property of connectors. When the main joint moves, that motion has to transfer through all of the other joints attached to it. The joints will be easier to stretch (and to break) the shorter the rods that are connected to the main joint are.
Note that this is not a glitch, but is frowned upon by the community. The run-time behaviour is modal and, in the first example below, alternates betwen snake behaviour and falling apart.
To restate the construction technique: An object with a joint is provided as one 'end' of the snake. Water rod 'A' is hung from the 'end' joint. Then water rod 'B' is hung from the same joint on rod 'A'. Then rod 'C' is hung from the joint rod 'B'. ... Then rod 'Z' is hung from the same joint on rod 'Y' and then another object can be hung from the joint of rod 'Z'. Initial thoughts would suggest that all these many joints should be in the same place, however the slack in the joints allows 'B' to move relative to 'A' and 'C' to move relative to 'B'; this all builds up so that 'Z' can be a long way from 'A'.