Wasp, bee and hornet nests Wasp nests are the most common. Occupied nests should not be disturbed and if you encounter one you may wish to consider abandoning the visit because being stung (or trying to avoid being stung) could put you at risk of a fall. 2.4 Safety underground Survey or monitoring work in caves and mines requires particular attention to safety because the potential fora serious accident is probably greater than in buildings. Inexperienced workers must seek advice and practical guidance from an experienced caver, who should have the appropriate equipment and be familiar with good caving practice. Guides to good caving practice and techniques are available from the mining and caving organisations listed in Appendix 6. A glossary of caving and mining terms is given in Appendix 2. A sample risk assessment for entry into disused mines is given in Appendix Training in underground techniques, with a firm emphasis on safety, is available from a variety of sources. Courses specifically for bat workers are organised at irregular intervals by some bat groups. Caving clubs and outdoor centres often run a range of courses, and videos and books are available on simple and vertical caving. Specialist caving equipment suppliers can also bean excellent source of advice on the type of equipment that will be required. The following safety rules are expanded from safety codes produced by caving and mine-history organisations. 2.3 SAFETY IN AND AROUND BUILDINGS 27 • Never go alone. Even the simplest accident can immobilise alone caver and lead ultimately to death from exposure. Don’t split up underground and always ensure the party is within shouting distance. A party of four is the minimum recommended size, so that one can stay with an injured person while two go for help. • Always tell a reliable person where you are going and what time you expect to be back. • Take spare lights. Although purpose-built mining or caving lights are reliable, accidents and equipment failures do happen. Make sure that there is always at least one spare light in the party and it is preferable that each member carries their own spare. Chemical lights (Cyalume) can be carried for emergencies, though their low light output restricts their usefulness. • Wear appropriate clothing. Caves and mines are generally between 8 and C (although some sites, e.g. disused railway tunnels, can be cooler C, so for dry caves normal outdoor clothing is appropriate. Wet sites are more of a problem because heat loss through wet clothing is considerably higher. Wet or dry suits are the preferred solution for many keen cavers, but a good combination for bat workers is a waterproof oversuit together with either a fleece undersuit or old clothes and thermal underwear. Wellingtons are often the best footwear. • Take appropriate equipment and know how to use it. Many levels, adits and caves can be entered without any special equipment, but even apparently straightforward horizontal passages can contain hidden hazards, such as unsafe floors and roofs, shafts covered with rotting timber or deep water. Abandoned mines should always be treated with extreme caution and old timber or metalwork should never be touched, let alone trusted. Vertical shafts should be attempted only with adequate safety equipment and never without proper training on the surface beforehand. The use of wire caving ladders (electron ladders) and SRT (single rope technique) should never be attempted underground until full proficiency is achieved above ground. • Try to obtain a survey map of the site before the visit. These are sometimes available through local caving clubs. In all but the simplest sites it would be prudent to take a guide who knows the system because it is quite easy to get lost underground.