JonathonD,
You are quite right "trust" is a very human concept. and it is my trust that is suspect, not the animals.
I hated the idea of having to kill this snake, I just could not get it out of my garden, and had no idea as to how it got there.
I do not trust a wide variety of other animals, and humans as well, but we were talking snakes and so that was what the comment was related to.
However I do relate totally to the poem by D H Lawrence (1885 to 1930), titled "Snake":
" I thought how paltry, how vulgar, what a mean act, I despised myself and the voices of my accursed human education'
and the last lines.
"And I have something to expiate: A pettiness".
No I did not trust that animal, but I did not like the fact that I did not.
Alan L.