So I think it could mean one of two things.

1. If it is actually meant to be a non-functional mousetrap, then skepticism of "Hantavirus" is perfectly justified and is just free cheese. I think they're saying that it is good to be skeptical of these things, like Covid, because...they are lying about it because reasons.

On the other hand, it's likely they just didn't know how to draw a set mouse trap, and a lack of clear labels is probably a sign that this is the case. I've never seen a right wing cartoon that respects their audience's intelligence and ability to pick up subtlety.

If so, point 2. It is probably meant to represent how skepticism is bait for the hantavirus "trap", I would guess because they think that any "free thinker" who wants the freedom to choke to death as their lungs fill up with fluid is "too dangerous" and so the insidious Them must be planning to...do something to anyone expressing skepticism of this virus, probably the usual right wing fears of being treated the way they treat others.