It's not that you can't crush ants, but there are several reasons why it might be harder than you expect, and why doing so is often ineffective and even counterproductive.
The Exoskeleton Factor
Ants possess a surprisingly robust exoskeleton. Some species, like the velvet ant, have exoskeletons so tough that entomologists struggle to pierce them with pins. https://buffalobayou.org/tag/red-velvet-ant/ While not all ants are this resilient, their exoskeletons provide significant protection against simple crushing. This makes it difficult to effectively squish an ant with just your fingers, especially smaller ones.
Pheromone Release: A Warning Signal
Crushing an ant releases pheromones, chemical signals that alert other ants to danger. [28-Jul-2022] This can lead to a swarm of ants investigating the source of the disturbance, making the initial act of crushing one ant lead to a larger problem. https://www.quora.com/If-I-regularly-kill-groups-of-ants-in-my-room-will-other-ants-from-the-same-colony-keep-on-coming-to-my-room-anyway This is often why killing ants individually is ineffective; it triggers a more significant response from the colony.
The Odor Factor: Not Always Pleasant
Many people report a distinct, unpleasant odor when ants are crushed. https://www.reddit.com/r/BrandNewSentence/comments/15d0ezv/yall_out_here_being_able_to_smell_ants/ This smell, also related to pheromones, is another reason why many choose to avoid this method of ant control. The smell is not always the same across ant species. https://www.reddit.com/r/evolution/comments/rjh9jh/smell_of_ants/
Ineffective Pest Control
Simply crushing ants is often not an effective long-term pest control solution. It addresses a symptom but not the root cause (e.g., a food source attracting the ants). More comprehensive strategies, like removing food sources and using targeted ant baits or insecticides are generally recommended. https://www.wweek.com/news/2017/05/17/why-are-sugar-ants-so-bad-in-portland-how-do-you-get-rid-of-them/
