I find that some aspects of their general character are conflicting. You state outright that they have an inherent fear of larger species, yet at the same time they are apparently curious to the point of that caution being abandoned. While it might be a bit of a cliche for smaller things to be generally wary and cautious, it's fairly justified because when you're that small almost anything can prey upon you. As a species, it would be better for their survivability if they had an aversion to foreign things entirely. But that's just my two cents as far as that goes.
Other than that, I commend you on the effort and can honestly say it would be an interesting species if implemented.