it's not possible for me to experience the Umwelt of comet and hilde. 
they are probably better at coming into my Umwelt. 
sometimes i think we are companions of different worlds.  
each human is an Umwelt, and each dog too. we're all mysteries to wonder upon. 
if we are all separate, we are also all one. one grand mystery to celebrate 
with love and compassion. sometimes i think that the Umwelt is only a human notion, and we are all really of the same world, and in it, come what may, even though we forget. 
if we are experiencing different things at the same time i know we are also interleaved, enmeshed, happily tangled as tender roving rootlets. and we are creating a world together. all may be vanity in us humans, but if wishing would make it so, i would enter their world with pleasure and fascination, and i imagine that is also how they would too.
be it as it may, i know one thing: i sure do think of them a lot. 
maybe it may be impossible for me to directly experience the Umwelt of comet and hilde, but i feel sure i am in it.