RANCH GATES
Leave all gates as you find them. Many Texas ranches have "bump-gates."  You have to drive up to the gate until the bumper touches it, then smoothly accelerate through the gate without hesitation.  If you don't know how to do this, have someone hold the gate open as you drive through or you may damage your vehicle.

SNAKES
Please do not kill rattlesnakes and please do not take firearms into caves. Rattlesnakes are natural inhabitants of some Texas cave entrances. As National Speleological Society members, we are committed to leaving cave life alone except for scientific study and conservation reasons. Rattlesnakes are highly poisonous and are common on the Texas karst. Leave them alone on the surface too - they belong there.

We know of no caver ever being bitten by a rattlesnake in a Texas cave, but that's because we throw lots of rocks when we go in. This stirs the snakes up for awhile, but then they usually crawl away from the noise. This is safer than crawling into a cave with a gun in hand. Always throw several rocks into a cave before entering and listen for the tell-tale rattle. Don't assume you're safe if you don't hear one. Be especially careful throughout the twilight zone-pit entrances are no exception! And don't forget to watch for snakes when you exit the cave too. Should you find a snake you can generally get around it without much trouble. Unnecessary harassment of snakes puts you at risk. Please do not kill cave scorpions. Many Texas caves are home to Pseudouroctonis reddelli, a troglophilic species. They are purplish-black, up to about 6 cm long, and occur on walls, ceilings, and cave floors. They are usually not aggressive but keep away from them anyway. Little is known of their toxicity. Only three cavers have reported being stung, two with no reaction (except sharp pain) and one with a moderately bad reaction.

FIRE ANTS
The red imported fire ant, Solenopsis invicta, began invading caves near Austin and San Antonio in 1988.  It is a pest that originated from Brazil and has been spreading across the southern U.S. for decades. None have been seen yet in caves on the Edwards Plateau.  These aggressive ants go into cave entrances seeking moisture and food but they maintain their mounds outside.  During the winter they retreat from the caves.  Be very careful when crawling into caves in the Balcones Fault Zone because fire ant stings are painful and raise small blisters.

It helps to wear a thick, long-sleeved shirt and gloves, then have a friend brush the ants off of you once youre inside.  Do not use pesticides in or near a cave - this will not help you quickly enough and you may poison the cave ecosystem directly or indirectly.  For example, cave crickets come out to feed at night and they will take fire ant bait, which can kill the crickets.  One to four gallons of boiling hot water with a dash of detergent will kill most fire ant mounds quickly and almost completely.

BATS
Please do not disturb bats. Texas caves contain several species of bat: Mexican free-tailed bats, cave myotis, tri-colored bats, and Peter’s ghost-faced bat. If you encounter bats in a cave, please try to avoid them.  Move quietly and quickly out of their way and warn others not to enter that area.  Do not shine your lights on the bats.  Texas cavers should usually enter bat caves at night to avoid problems during exploration.  Biologists who need to identify bats should use red filters on their lamps and move softly.  Many species can be identified and measured without actually touching the sleeping bat.

Ammonia vapors in Mexican freetail bat caves are hazardous to cavers the concentrations easily exceed the known safe levels for industrial workers.  Most cavers do not enter the large roosts, but those who do should wear an industrial-type, air-purifying respirator equipped with ammonia cartridges, to which the individual has been professionally fit-tested in a test chamber.  Such respirators do not work if facial hair protrudes through the rubber edges of the mask, no matter how hard you cinch down the mask.  Ammonia poisoning can severely scald the lungs and land you in the hospital.

HISTOPLASMOSIS
Histo is another occupational hazard for cavers; it is a serious fungal infection of the lungs, eyes, or other organs, and it can be life-threatening without proper treatment.  Bat caves often have Histoplasma spores.  Cavers who have not been exposed to "histo" should think twice about entering bat caves in Texas or Mexico.  Novices and cavers from the northern U.S., Canada, and Europe are especially at risk.  Symptoms usually begin about two weeks after exposure and include fever, headache, shortness of breath, painful breathing, and miasma.  The diagnostic blood test can give false negative results. Antifungal prescription drugs, such as ketoconazole, are effective against the infection.

RABIES
Rabies is a fatal viral disease carried by bats and other mammals . Far fewer than 1% of bats have rabies, but cavers should not handle bats unless they have taken the preventative human-diploid-cell vaccine.  Grounded bats are more likely to be sick, so dont pick them up.  Although a study in a Texas bat cave showed that caged animals can contract rabies by just breathing it on aerosol droplets, no human case of rabies by this route of exposure has been proven.  However, this may be because most cavers receive only brief exposures to intense bat cave atmospheres.  If you are bitten by a bat, immediately wash the wound with soapy water and get immediate medical treatment.

BAD AIR
Some Texas caves have "bad air" or "foul air."  This usually means reduced oxygen and elevated carbon dioxide.  Such caves tend to be in the Ellenburger Group limestones (Burnet and San Saba counties) and the Austin Chalk (Bexar and Medina counties) but rarely in the Edwards Group limestones.  Some bad air caves are physiologically stressful even to well-conditioned cavers, and a few are quite dangerous. The air tends to be better in the winter and spring.

In certain areas of Texas, cavers carry Draeger carbon-dioxide detectors, oxygen meters, or butane lighters for the "Bic Test".  The Bic Test uses the lighter to test the air - poor air conditions result in a large gap between the nozzle and the flame.  Exit the cave if the Bic won't light. Bad air affects each individual somewhat differently, but can cause panting, headache, exhaustion, confusion, loss of judgment, and even panic.  Most cavers don't notice the CO2 until it reaches 3% (about 100 times normal), but it can become very stressful at 6% or more.  Usually the CO2 increase is accompanied by a similar O2 decrease.  Recovery is rapid upon exiting the cave, but this can also result in nausea.  Certain notorious bad air caves, especially pits with stratified atmospheres, should be avoided or left to those with scuba equipment.