Single sensors may detect overall light levels. In the case of suspected rupture, it can also reliably detect retroperitoneal fluid. Likewise, most benzodiazepine drug tests will not reliably detect lorazepam. Smoke detectors sometimes do not detect the fires. Because the Higgs boson decays very quickly, particle detectors cannot detect it directly. It is better able to detect and avoid predators. These photocathode devices do not detect temperatures, but rather infrared radiation variances. Using bacteria, researchers can detect pollutants in samples. Ultrasound may also detect fetal organ anomaly. They can detect predators and warn others of their presence. Ultrasound examination may also detect the problem. For E-ZPass users, sensors will detect their transponders wirelessly. Several types of fish can detect ultrasound. Birds can also detect slow moving objects. It can detect and correct single-bit errors.