Spiders!

[karma mechanic]

Yesterday I spotted what looked like a brown blob on my car, on closer examination it was a dense ball of tiny baby spiders.
I took a piece of paper and coaxed the blob onto it, it seemed to stay put so I started walking towards the garden to transfer it to a bush. All at once the blob split up and a whole load of spiders were going in all directions...I managed to shake the paper over some shrubbery and they all went everywhere.

Just now I looked to see if any were still around and this is what I saw at the top of the shrub:



The Blob is reconstituted.

So if a predator came along it could eat a whole load of spiders in one go. If they were scattered around it seems much more likely that some would make it. So what's the evolutionary advantage of making a blob?

[eybic]

I guess it could be to make the "object" look bigger then perhaps the WTF as they all run in different directions????

[karma mechanic]

eybic said:

I guess it could be to make the "object" look bigger then perhaps the WTF as they all run in different directions????

Probably. It made me jump!

[eybic]

I bet. I'm not "scared" of spiders but having seen a group "explode" like you have I was debating whether to run away

[tapkaJohnD]

Same tactic as animals that herd or flock.
The whole group may attract predators, but in the confusion most are likely to get away. For instance, lions are successful in less than one in five hunts.
The sudden scattering is typical of such a tactic.

And that 'brown blob' may appear as a bird dropping, unattractive to an insect eater.
So two adaptations that will protect the brood.
John