Alarm and alert odors

Odors are important in the attraction of the sexes, and men and women differ in this. Women (American college students) ranked body odor as more important than any other factor in attraction to men, except pleasantness. Men, however, ranked good looks highest, except for pleasantness (Herz and Inzlicht, 2002). 

The apocrine glands in the axilla can secrete enormous amounts of steroids such as dihydrotestosterone and pregnenolone (Brooksbank, 1970). Three single steroid compounds have also been tested on T-shirts. Surprisingly, both sexes attributed androstenol to females. Two other synthetic compounds were attributed to one or the other sex, depending on concentration, and one was perceived as very negative. Androstenol and the two synthetic compounds have very low olfactory thresholds for humans. 

The compound responsible for much of the underarm odor is 3-methyl-2-hexenoic acid in both its (E) and (Z) isomers (Zeng et ah, 1991). Breath can also communicate gender information. However as with axillary odor, breath from men tends to be classified as stronger and more unpleasant than that of women Doty etal, 1982). 

We have to distinguish alarm signals emitted hy a disturbed or stressed, hut not captured, animal from disturbance signals and chemical cues from injured or captured individuals, termed damage-released alarm signals (Chivers and Smith, 1998 Mirza and Chivers, 2001). 

Alarm substances in fish are extremely potent extract from 1 cm minnow skin creates an active space of over 58 000 liters of water (Smith and Lawrence, 1989). 

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