Avoid creating the situation
With Brachypelma hamorii, prevention matters more than trying to predict whether a particular spider will bite. Keep the enclosure secure and give the spider a clear route back to its retreat during maintenance.
Do not handle a Mexican Red Knee for routine care. Feeding, water changes and rehousing can all be completed without holding Brachypelma hamorii in the hand.
Venom and bite risk
Brachypelma hamorii is venomous, but bites are not generally considered medically significant. urticating hairs are the more common concern
A bite from Brachypelma hamorii should be treated seriously enough to avoid in the first place. If a bite occurs and symptoms are significant, seek appropriate medical advice rather than relying on hobby anecdotes.
Hairs and other defences
The species record for Brachypelma hamorii notes urticating hairs. Avoid exposing skin and eyes to loose hairs during maintenance, and take particular care when moving old substrate.
Do not deliberately provoke defensive behaviour in Brachypelma hamorii to test temperament. Threat postures, sudden movement or hair-kicking are signals to stop crowding the spider and give it space.
Maintenance tools
Use long tools for Brachypelma hamorii when they give useful distance, and keep a catch cup ready whenever the enclosure is being opened for more than a quick water change.
Arrange the Mexican Red Knee enclosure so food remains and the water dish can be reached without dismantling the main retreat. That reduces repeated disturbance and close contact.
Rehousing
Prepare the destination enclosure completely before moving Brachypelma hamorii. Close nearby doors, clear the work area and have the catch cup and guiding tools ready before the old enclosure is opened.
A controlled cup transfer is safer for a Mexican Red Knee than trying to move the spider by hand. The goal is a short, predictable route from one secure enclosure to the other.