What effect will the night tube have on London Underground's resident mice?

What will the mice who live in the Tube network make of the new all-night service? Half a million of them are thought to have made the London Underground their home. It must have been a surprise when the Victoria and Central lines keep running all night for the first time on 19 August.

Londonist is concerned the mice “are unlikely to get any sleep” with the new Night Tube, and may move to the District line instead. Yet a number of scientists point out to the New Statesman that mice are nocturnal creatures, most likely to sleep while the lights are on and the trains are running.

So will they get on board with the change – or make a run for different platforms on other lines?

The bad news:

“When the Tube’s away, the mice will play,” is how the rhyme (almost) goes.

Many have come to know – and even love – the mischiefs of the mice who stream off the tracks and out of the tunnels as the stations close at night, in search of discarded morsels of Maccy D. And until now, they’ve had a good few hours to conduct such galavanting in peace. But the new system means they will have to re-structure their sleep and foraging cycles, or “circadian rhythms”.

“The presence of night trains should upset several of these entrainment factors (or zeitgebers; “time givers”) leading to disturbances in their behaviours,” explains Professor Patrick Nolan, from MRC Harwell, an international centre for mouse genetics.

“When you fly across the Atlantic, for example, it takes a few days to adapt, you feel a bit groggy, don’t perform as well as you usually do, don’t eat well, etc. You soon adapt to the change. But if there are constant disruptions like this, the effect may be more severe and long-lasting. And this is how the schedule changes in the Underground might affect the resident mice.”

So it’s the constant switching between the week and weekend schedules that could leave the mice – and Tube drivers – most cheesed off. Agoraphobia (fear of open spaces) and photophobia (sensitivity to light) are two possible effects of the resulting anxiety, and their mating patterns and liver functions are also likely to be disturbed.

The good news:

Yet it is unlikely mice will be leaving the Night Tubes for good.

The more time we humans have to drop our dinners, the larger the menu becomes for the mice (researchers tell me that strawberry milk and Wheetos are particularly favoured fare).

“Mice are active most of the time – so more trains at night hours will not make such a difference to them,” say the RSPCA’s wildlife officers. “In fact, it may help as it may provide more foraging opportunities.”

They’ve also faced worse before. The London Transport Museum reminds us that, during the Second World War, cats were employed to counter vermin on the network (spot the cat in the 1940s TfL workers’ canteen below).

Credit: London Transport Museum.

For Dr Samuel Solomon at UCL, there is plenty to suggest the mice will successfully adapt. His study of mouse reflexes shows how they respond to various visual stimuli – and can start running within one-tenth of a second. “There might be cues they pick up – if people clean the station differently on Fridays, for instance.”

The tracks’ electric current may no longer be entirely switched off (if it ever was), but their whiskers’ sensitivity to vibrations could help them juggle their escapades to fit around the Night Tube’s less frequent service.

What Dr Soloman can’t yet predict is whether the mice will start to anticipate that Friday feeling: “It will be interesting to see whether they can learn that Friday is Friday”.

All in all, the Tube mice seem well set for the Night Tube’s new challenge. Who knows, they may soon gain the confidence of their 24/7 brothers in New York – and start ordering take-out…