Been meaning to post here for a bit. Might as well do it now.
Larch is definitely like Bluebell in a lot of respects, but he also borrows a page from Blackberry's book. He's notably intelligent for a rabbit, like Blackberry, but he has no good sense, no wisdom, to back it up. He'll charge into situations without a full understanding because he knows something is strange and he's curious as to what will happen. He likes stirring up mischief because he knows how and because he wants to learn how to do it better. There's a good chance Larch would drown in the process of figuring out that wood floats. He's an intelligent fool. Or, that's what I have in mind anyway.
I was kind of thinking that since, presumably, a dam has been taken down upstream, there might be flooding or at least leakage in their burrows or something. Wet soil isn't much good to be scurrying around in, for various reasons.