From a farmer reported to the RSPCA for allowing his sheepdog to herd his sheep to rescuing snails from a family race, humanity's interventions for the noble cause of animal rights aren't always for the best.

Britain is a nature of animal lovers, and many have understandable concerns about the use of animals for entertainment, pets being abused or the treatment of farm animals.

But a tranche of incidents in which members of the public have tried their best to do the right thing - only for the results to be disastrous - have prompted pleas for Brits to use common sense. 

This week, activists took a moral stance to ensure the cancellation of a family-friendly snail race in Nottingham even though it is actively encouraged by wildlife trusts to engage families in the natural world.

Just days later a respected family farmer in Devon received warning letters from the RSPCA after a local reported his sheepdog - for herding his own flock. 

Elsewhere a marine biologist stole a crayfish which she assumed was to be eaten, when in fact it was a beloved education tool for children - only for its tankmate to die of loneliness days later. 

And a distressed magpie, which has been trapped inside a Sainsbury's superstore for two months, has seen local do-gooders campaign against an application to euthanise the bird, prolonging its suffering.

These are just a few cases in which animal activists have been accused of abandoning all common sense in favour of an ethical crusade which flies in the face of practicality - or is just plain wrong.

Now the RSPCA has reminded animal lovers: 'Sometimes, not intervening can be the best thing to do.'

In Nottingham, a much-anticipated snail racing event had to be called off this week after animal rights campaigners complained it could injure participants.

But similar races take place regularly across Britain, which is also home to the World Snail Racing Championships, and it is even condoned by wildlife trusts as a fun, family-friendly pasttime.

People were encouraged to bring in snails from their own gardens for the event, part of Nottingham's Great Big Green Week at the city's Central Library.

It was supposed to be an 'snail racing demo' on an electric race board that was both 'light-hearted' and 'educational', but activists claimed the 'desperate attempt to engage children' was cruel. 

Wildlife experts have previously not raised any concerns about snail racing, with some trusts even openly advocating it as a fun, family activity that engages children in nature.

The Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust has an entire webpage devoted to snail racing, which it calls a 'family activity', and encourages nature lovers to test whether snails or slugs are the faster mollusc.

It gives guidance on how to ensure the safety of snails throughout, advising to look for them in dark, damp places, handle them gently and only for 15 minutes at a time, and always return them to the spot where they were found. 

Yet in a social media post, Nottingham Animal Coalition said it was 'absolutely shocked' and said snails need to be picked up in a specific way to ensure they are not detached from their shells or injured.

The post added: 'So why, when snails have developed all these methods to protect themselves, would we encourage children to pick them up and handle them, potentially causing injury, displace them from their natural habitat... and then RACE for our entertainment?'

Speaking to BBC News, coalition member Kerry Kane, 33, said: 'It was really irresponsible because of the potential injury you could cause to a snail by picking it up wrong.

'You have to gently tap or stroke the shell, so the snail's foot retracts, and then it's safe to remove them and then place them in the direction they were going in.'

It sparked outrage in some residents, pushing the council into a climbdown which saw the event cancelled altogether. 

A spokesperson apologised both for cancelling the event, and to anyone who was upset by 'genuine concerns about the welfare of the snails involved'.

Snail racing originated in the UK and sees hundreds compete in the World Championships, held each year in in Norfolk. 

Professor of Evolutionary Genetics at Nottingham University and renowned snail expert Professor Angus Davison told the Daily Mail that 'as long as you're careful and respectful of snails, there is no risk at all'.

He said snails should always be handled with care and returned to where they were collected from, adding: 'If you ripped a snail off a wall while it was crawling along, you could damage it, but I don't think any reasonable person would do that. Anyone who's interested enough in snails to have a snail race is going to carefully take them off the surface they're on, and look after them until they get to the race.

'It's a good learning experience, because you get close to wildlife. I do sympathize in the sense that the snails are wild animals, and they're not used to being around and close to people, but just shutting off wildlife is not a good thing.

'My concern is that a few people complained [and it was cancelled]. The Council could have defended themselves if they had something prepared in the background to respond to that, but I don't think they did. So that's how they got into this situation.'

Even more bizarre is the case of farmer Tom Trueman, 42, who received a warning from the RSPCA after his sheepdog was seen rounding up his sheep.

The organisation had received reports from a concerned driver that Mr Trueman's dog was 'worrying' his flock in Buckfastleigh, Devon. 

He was sent two pamphlets alongside the complaint titled 'dog behaviour' and 'how to look after your dog' and was required to speak with an RSPCA inspector before he could clear up the misunderstanding.

It's not the first time he has received a report from the RSPCA, following another 'frivolous' incident which saw an officer visit his farm to check on his horses.

He said: 'Around 20 years ago we had two very elderly former racehorses, we used to put them out for grass for around two hours a day whilst we cleared out their stables and give them some space to run and be outside.

'A report claimed our horses were outside with no grass - and when the inspector came to see for himself he saw how wrong it was!

'It is getting a bit daft in the RSPCA: they do an important job but a lot of people abuse their system by reporting farms just because they don't like farmers.

'The next thing you know I'll be reported for verbally abusing my sheep!'

Misguided interventions by activists can not just go too far, but even end in criminal conviction.

In April, marine biologist Emma Smart, 47, admitted one count of criminal damage after she stormed into a restaurant and stole a crayfish she assumed was going to be killed and eaten.

But in fact, owner of Catch at the Old Fish Market in Weymouth, Dorset Anthony Cooper had owned the creature for more than two years and kept it for educational purposes.

Smart forced her way into the restaurant as guests were leaving and made a beeline for the tank. 

She grabbed the crustacean, which Mr Cooper had used to educate children visiting the Catch, before barging past two members of staff who tried to stop her leaving with the showpiece.

The activist then released the creature in the harbour a few yards away. It is not known whether it survived the ordeal as it was never seen again, but it is feared the shock of being dumped into freezing sea water likely killed it. 

Days later the crayfish's tankmate was reported to have died of loneliness. 

At court, Smart's barrister said: 'She acted on impulse. She cares very deeply about animals and marine welfare and this was the driving factor behind her committing this offence.'

She was handed a conditional discharge and a three-year restraining order banning her from going within 10 metres of the restaurant or approaching staff or guests.

A single magpie has held staff at Sainsbury's in Godalming, Surrey, captive for almost two months - with experts unable to intervene to end its suffering due to its protected status in law.

The bird, which has been frequently spotted in the rafters of the superstore since its arrival in mid-April, is described at being increasingly distressed due to being unable to escape, and has sparked concerns over hygiene and food safety at the retailer.

Supermarket staff have been unable to catch the magpie humanely and its protected status as a wild species mean it cannot be killed or captured in a way that risks any harm to it without a government-approved licence.

Multiple efforts to solve the problem, including attempting to catch the bird in a net, are reported to have failed - and concerns about its welfare means Sainsbury's has been forced to look to a more permanent solution.

It is claimed that the Godalming branch of Sainsbury's has quietly applied for a licence to have it destroyed - but the move has infuriated a small band of animal rights activists who want the lengthy efforts to rescue it to continue.

One, Catriona Wiles, claims the supermarket has been given a viable solution for 'humane capture and removal', and the offer of aid from wildlife charities, and hit out at alleged 'unnecessary resistance'.

But experts have pointed to the magpie's behaviour as signalling it is suffering, and said the species' intelligence allows them to easily evade attempts to capture them.

Trevor Weeks, founder of East Sussex Wildlife Rescue, told the BBC that magpie capture attempts are only successful in 60 per cent of the buildings they are called to, and that it is common for them to die before they can be rescued.

He added the birds are only 'destroyed' if all other avenues have been exhausted, and the appropriate licence has been obtained.

A Sainsbury's spokesperson did not deny that the supermarket has applied for such a licence. They said: 'We take animal welfare seriously and are working with specialist contractors to remove a magpie from our Godalming store, in full compliance with animal welfare regulations. 

'We have regular checks in place and appreciate our customers' patience while we work to resolve this as quickly as possible.'

It's not just individuals whose bid to protect animals can go wrong - Animal Rising previously had to cancel plans to 'rescue' hundreds of animals from farms over the harm it could cause.

The group planned to train more than 200 people to steal the livestock from RSPCA Assured farms - sites that already fully comply with the organisation's strict welfare code.

After the plans were exposed there was outrage as experts warned such interference would cause distress to the animals uprooted from their surroundings and also risked spreading serious diseases. 

Mo Metcalf-Fisher, External Affairs Director of the Countryside Alliance said at the time: 'It is bizarre that a group which supposedly supports animal welfare would attempt to disrupt a scheme designed to ensure high animal welfare standards.

'In a sad irony, these stunts actually risk threatening the welfare of livestock.

'We hope the authorities take immediate and robust action to tackle this criminality.'

The RSPCA said it welcomes those trying to help and examines all reports of suspected animal suffering, but warned animal lovers that 'sometimes, not intervening can be the best thing to do'. 

A spokesperson said: 'We're a nation of animal lovers, and it's always great when people look out for animals and want to help them.

'When people report suspected animal suffering to us, we always look into and, if necessary, investigate any complaints where the welfare of animals is being compromised.

'There's only one RSPCA officer per 180,000 people - so our frontline teams must prioritise incidents of serious cruelty and neglect. That's why we have launched an online tool, to help people understand when they need to sound the alarm about animals - and who to contact.

'There's many steps people can take to help animals themselves - and programmes like our Summer of Kindness scheme helps people understand the little things they can do for animals in their communities. 

'But sometimes, not intervening can be the best thing to do too. Whether that's a healthy seal pup on a beach, a fledgling bird or a lone deer fawn, sometimes the best advice is to keep an eye and leave well alone.'