I've noticed, like many others, that dogs hate bicycles and tend to bark or attack them and their riders.

From my observation it's not as simple as it first appears; sometimes I've noticed that dogs simply don't register a bike approaching them, and are then really surprised when nudged with the front wheel even though they've  seen it coming and presumably smelled the rider approaching too, and the rider was shouting and ringing a bell. In these cases, though, stamping a foot down works wonders.

It seems to be all about footfalls/vibration being the key factor that most dogs pay attention to. They see a person apparently gliding along without any obvious footfalls and it either freaks them out, or they completely ignore it and don't perceive it as a large object approaching.

My question is "why should this be?" What possible evolutionary reason is there for ignoring the sense of sight, smell and hearing in favour of vibrational cues? Is it that chasing prey through sunlit and dark areas renders sight less effective than vibration sense? Is it that in a wild pack of dogs, there's constant noise and confusion so footfalls are the most reliable way of sensing a threat?

What is going on here?

None of the countless species of animal in existence has three legs. Creatures such as the kangaroo and the meerkat use their tails for balance, but a tail is plainly not the same as a leg. This pattern does not apply only to mammals - other kinds of animal have an even number of legs, too. Why wouldn't having three legs work?

Monika Hofman, London, UK

My daughter is nearly 4 weeks old and she has that 'new baby smell' which my wife and I find absolutely lovely. We have so far only bathed her in clean water (no baby-wash or soap) and have only used lotion a couple of times when she's had dry skin, so her smell is all her own. Is this some sort of evolutionary device to encourage us to take care of her? Would other people find our baby's smell as lovely?

There seems to be no reason to suggest that a creative mind can help us survive in nature.

eg possibly they would gain from the contents of vomit - spreading the spores. this would presumably apply only to the ones that look 'innocent' (& taste ok).

possibly they would gain from the breakdown of the victim's body - minerals, etc. also maybe contents of vomit - spreading the spores. this would presumably apply only to the ones that look 'innocent' (& taste ok).

These are the photographs of a strange bug I came across during my stay in Manipur state of North East India. The dorsal view of the insect resembles a human face.  This semblance to human face doesn't appear to be by chance. What evolutionary advantage could have favored such an adaptation.