The question https://skeptics.stackexchange.com/questions/19036/do-fish-swarms-show-some-intelligence was asked, and it's a biology question. I wrote a comment "This question belongs on Biology.SE" and then flagged it for migration. The OP also put a comment that they will ask for migration.
Oddthinking then posted a comment:
Closed as off topic. No need for a migration. If you want to post it to Biology.SE, go ahead and cut-and-paste (but check their FAQ - I suspect it is off-topic there too.)
Disregarding the issue of whether the question in on or off topic on Bio.SE. Assuming we have a question that is off-topic here, but on-topic on another site, what are the criterias for a migration, and are there scenarios where a deletion and a reposting on the appropriate site are better than migration?