I suspect someone deliberately ruined my experiments by poisoning my lab insects. What should I do?
I assume you're doing CO2, in which case you frame it as a serious safety concern and insist on looking into it. You're in an enclosed space with an asphyxiant that appears to be leaking. This is a critical health and safety issue and should be treated accordingly.
It's unlikely in my opinion that you are being sabotaged but if you are whoever is doing it will stop if these issues are investigated