Our cat loves them,
our dog hates them,
our donkeys are scared of them.
Cat will happily nap on top of you in the hammock. My cat that died last year would make her daytime nest in our hammocks and was irritated when we wanted to get in; it disturbed her.
Dog will sleep right between our hammocks on the floor when she's feeling lonely and the donkeys will run like the devil is chasing them if there is nobody in the hammock. Now then, if someone is in the hammock, or there is a tarp covering it, they will curl-up right next to it. No clue what's wrong with those boys?