I don't think it's a trap to be honest, although if I was going to do the spider thing I wouldn't just write a small mini factual report kind of thing. Take it and do something unique with it.
I'm think you meant the spiders is the easier essay topic, but I'd argue the first one is easier. Smaller classes = more personal = better learning experience. Research opportunities = way to further education in a less typical, more challenging, possibly ground breaking area, providing good experience for when you're graduating and going into an actual career. Just seems to easy, where as spiders would take some more creativity I think.
Not sure what your major is, but if you're going into a STEM major, essays really don't matter