Not sure why anyone would think that. I suspect that nearly all organisms, and certainly macro organisms, experience fatigue and metabolic stress over time. So I do not presently think it likely that ‘ants never get tired’. read more
We know ants will walk just fine with broken or partially-amputated legs (although they have trouble doing the same things, as you would expect), so I doubt they would notice if their leg was tired. I also doubt insects get muscle pain at all. read more