[evan_au]

Isn't there an example in mice.  When they encounter cat urine, they smell it, and get infected by a virus.

You are thinking of Toxoplasmosis, which is a protozoa, which is larger and more complex than a virus.
- Yes, it does cause a change in behavior in mice, making them (lethally) bold
- It also infects humans, through emptying cat litter. There have been studies that suggest that Toxoplasmosis also affects human behavior. I recall one report that was done in the military and found a positive correlation between presence of Toxoplasmosis antibodies and the number of vehicle accidents. (Presumably this correlation would extend to the battlefield?)

Toxoplasmosis does modify operation of the immune system to enable it to spread faster.
- And SARS-COV2 modifies the immune system too, suppressing interferon production.

See: https://en.wikipedia.org/wiki/Toxoplasmosis#Parasitology

Rabies (mentioned above) infects the nerves and does drive animals crazy - to the extent that they are more likely to lose their natural fear of humans, and to bite them, thus spreading the pathogen.

See: https://en.wikipedia.org/wiki/Rabies_in_animals

(Overlap with Colin2B...)

[set fair (OP)]

Could Covid-19 cause behaviour changes in humans. Such as pulling off face-masks, going up to each other, embracing and breathing over each other?

We already saw that in former President Trump.  As soon as he got out of the hospital, he triumphantly ripped off his face mask, and started holding political rallies, proclaiming that he would go through the crowds kissing anybody.

Other viruses like Rabies certainly cause behavioral changes to increase the spread.from host to host.

When you mention Rabies, that virus is too powerful, as it kills its hosts more than is good for wide-scale spreading.

Hence it is not very prominent in terms of global viral success.

From a viral viewpoint, isn't Covid-19 much more efficient, as it infects more hosts without actually killing them.

But the Rabies virus thinks soffitication is a the measure of success and has little time for chavs like the corona viruses

[set fair (OP)]

To be shed they must exit the body and hitch a ride om a droplet or aerosol.

And how do they arrange to do this (or to not do it)?

Sorry to be so long replying - suffereing the slings and arrows of outragious immoderators.

How they might arrange to do this, is what I am hoping to figure out. The reason for the question was to find out if there were any viruses which are known to do this and investigate from there.

[Bored chemist]

To be shed they must exit the body and hitch a ride om a droplet or aerosol.

And how do they arrange to do this (or to not do it)?

Sorry to be so long replying - suffereing the slings and arrows of outragious immoderators.

How they might arrange to do this, is what I am hoping to figure out. The reason for the question was to find out if there were any viruses which are known to do this and investigate from there.

Do you understand the idea of a rhetorical question?

[evan_au]

I'm looking for any viruses which change their behavior...

Other viruses like Rabies certainly cause behavioral changes to increase the spread from host to host.

Lets clarify this - the virus does not change viral behavior from one mode to another.
The virus changes the behavior of the host organism.

[Colin2B]

I'm looking for any viruses which change their behavior...

Other viruses like Rabies certainly cause behavioral changes to increase the spread from host to host.

Lets clarify this - the virus does not change viral behavior from one mode to another.
The virus changes the behavior of the host organism.

Sorry, loose wording there might have given the wrong impression.
Yes, it is the host behaviour that changes. In this case a tendency to paranoia/aggression caused by the effect on the brain.

[CliffordK]

To be shed they must exit the body and hitch a ride om a droplet or aerosol.

There are a number of ways a virus might exit/enter the body.

We are familiar with respiratory viruses. 
However there are many other types of viral spread. 

• At least one virus is known as the "Kissing Virus"
• Blood borne viruses get spread by contact with blood, or various body fluids, perhaps sexual activities
• Fecal Oral viruses are common.  Good hygiene helps, but may not 100% prevent transmission.

Bacteria, of course, are different from viruses, but one can also discuss toxins, either produced during the infection, or produced in a food product prior to consumption.

[set fair (OP)]

My question was in the hope of finding a steer to find more information. Not a suggestion that I think the idea particularly likely. If there were a disjoin between viral load ans shedding, it could easily missed in a respiatoy disease like covid since, as far as can see, viral load for covid is inferred from swabs, ie shedding is used to infer viral load.

[Bored chemist]

My question was in the hope of finding a steer to find more information.

And we answered it.
Which part of "no" are you not understanding?

[Petrochemicals]

All viruses are trying to make a quick exit all of the time, it's the nature of viruses.