  The busy beaver is a well-known specific example of a non-computable
function. Whilst many aspect of this problem have been investigated, it is not
always easy to find thorough and convincing evidence for the claims made about
the maximality of particular machines, and the phenomenal size of some of the
numbers involved means that it is not obvious that the problem can be feasibly
addressed at all. In this paper we address both of these issues. We discuss a
framework in which the busy beaver problem and similar problems may be
addressed, and the appropriate processes for providing evidence of claims made.
We also show how a simple heuristic, which we call the observant otter, can be
used to evaluate machines with an extremely large number of execution steps
required to terminate. We also show empirical results for an implementation of
this heuristic which show how this heuristic is effective for all known
`monster' machines.
