astronomy cloud dark moon night planet sky view watch clock hours minutes time wall hand wrist blue railwaystation reflection bird love bird nature sparrow watching animal guard guardian mammal meerkat mongoose protect suricate zoo black close up hornet insect sampling wasp wings yellow advice alert announcement beware camera cameras cctv center centre closed-circuit-tv communicating communication extensive information informing lookout monitoring monitors notice notification observation observe safety security sign signage surveillance thorough under-observation video warning warning-sign watched white appropriate-behavior appropriate-behaviour be-careful care careful caution cycling cyclists disability disabled observant path pathways pedestrians risk risks share sharing signs track walk walkers walking watch-out alternative-way arrow blocked blocked-path danger detour directing direction discoloration go-around message wording words