You'll find it common as a buttercup.
Any animal anytime
is liable to (certain to, if you practise) 
mediate between your refined self
and all that you, in your intelligence,
can never define but feel subject to.

A finger of ivy insinuates
through the slightest crack. More than proof
your chamber is not hermetically sealed.
It's not so hard to step out of the space capsule:
just realise, as the birdsong clearly tells,
you're not halfway to Mars.