Working in the drain cleaning game, we naturally come across all sorts of peculiar things down drains – often because they are blocking them. We’ll quite often come across toys put down there by curious children, and it’s not unusual to find false teeth, phones, tools, paint brushes and ... things we can’t mention on a family website.

Dead animals aren’t that unusual either. They’re usually squirrels, rodents, birds, goldfish and the odd cat. But we’ve never been (un)lucky enough to find anything as terrifying as a piranha in our travels. Apparently one was found in Telford this April after locals complained about a fishy smell. Luckily the creature was dead, and we probably shouldn’t be too worried about being taken over by mutant killer fish (which are native to South American rivers, of course) because it had apparently been flushed down the toilet by an aquarium owner.

Another imported species popped up in Cleethorpes, Lincolnshire in 2013. The Mexican black kingsnake started to emerge from some homeowners’ drain cover and appears to have been a pet that escaped. It was caught first on video and then by a local reptile dealer. The species is not venomous but it is a constrictor, so next time you see one, it would be wise to call the emergency services and to definitely to avoid being constricted.

Our American friends have their own problem that’s definitely not imported. The alligator has been there much longer than humans have, and lives in modern-day Texas, Louisiana, Mississippi, Alabama, Georgia, North and South Carolina and Florida. And they don’t mind reminding us that it’s technically humans that are the unwelcome visitors. This 9-foot-long beast was found by maintenance workers in Sarasota, Florida, for example; and those lucky enough to own a swimming pool often find one of its cousins taking a splash.

What do Australians do when Paul Hogan is out of town and a friendly crocodile decides to make an appearance from out of the drains? They call in the wisecracking croc squad to see if they can do anything about it. Turns out they can – but luckily safety is at the forefront of their minds, as you’ll discover if you watch the video to then end.

And finally we go back to the States, in Cameron Village, North Carolina, where a CCTV drain inspection stumbled upon this otherworldly specimen in 2009. They took to YouTube to try and get an identification and the mystery now seems to have been solved. The pulsating beast is apparently not one but hundreds of beasts, probably some kind of worm. We hope you’re not eating when you watch the video.

Summer is nearly upon us, so many of us will be heading out to the garden to do a spot of titivating. It’s also a time when drain cleaners see a small peak in the number of drains blocked by soil.

Part of the problem comes during dry weather, when topsoil can turn to dust and get blown around on the breezes. Much of the soil dust that lands on the concrete of patios and paths will get washed down the drains when it rains. The small amounts will be carried away by the water and in some circumstances, especially when there’s only light rain for prolonged periods, the soil can settle as silt in the interceptor traps or areas with slow flow. This is how the blockages start. Even large municipal storm drains can get blocked during dry spells as there’s no regular flow to prevent build-ups.

Take care as well if you’re venturing out back for the first time since last autumn. You might want to give paths, yards and patios a good brush, but make sure you put any detritus in the bin or return it to the soil – it certainly shouldn’t be brushed into the surface water drain!

Another time you need to take care is when you’re hosing your borders. You can cause a large amount of splashing, and these dirty, clumpy soil particles full of roots, leaves, sand, pebbles and dust can quickly turn into a blockage in your drain, especially if they have been partially blocked by autumn leaves. A hose head with multiple settings can help here. Use a spray setting, not a soak or jet setting – this will minimise splash. If you have borders around a lawn, making sure there’s a drop of about 10–15 cm (4–6 inches) between the lawn edge and the soil. This will help keep run-off topsoil within the borders. Physical barriers can be bought to make sure there’s no collapse of the lawn edges.

Drain covers can be a useful way of keeping most of the soil, leaves and other detritus out of your surface water drains while allowing water through. They can be bought from all DIY stores for a few pounds, which is a sound investment in our book.