Tie
From WikiManual
Ties kare a nonphysical element in DB that produces a connecting force between bots. They are similar in essense to ropes tinging two bodies together. Ties are always a part of Multibots and are frequently used by Single Bot to steal Energy from other bots. A single tie can connect only 2 bots together. The maximum number of ties currently is 4, although this is expected to change in future versions.