Alec and Kit’s first day out with nursery. Mine too. I’ve never been able to go on trips with my eldest son Harry, six, because I’ve always had Alec and Kit, four,  to look after – a fact he is not slow to pick up on.

As he sizes up their picnics, the injustice of the situation hits him.

“They’ve got chocolate mini-cheddars!” Harry shouts. “That’s not fair.” A pause. “That’s not even allowed!”

I assure him that although there is some brown writing on the packet, this does not mean they are chocolate. It’s too late.

“You’ve never been on a school trip with me,” Harry shrieks. “Why do they get to go with you and I don’t?”

“It’s not fair! I’m never going on another trip unless you come with me.” Somewhere a door slams. As his school trip is next week I am doubly guilty at my impending parental no-show. I can’t fault his argument.

Our emotional hurricane passes.  Alec, Kit and I slope off to nursery, praying we are not boarding the coach as Harry and my husband pass on the way to school.

We needn’t have worried. Half an hour later, we parents are still milling around in the playground awaiting our instructions. The teachers emerge and remind us of the rules: No eating or drinking on the coach, no chocolate, fizzy drinks or sweets and toilet breaks at designated times only (slight concern over that one).

We head for the coaches – I spot a few parents dumping banned items in the bin. I am now slightly panicky about our dodgy looking mini-cheddars.

We are off, only half an hour late. Alec and Kit’s teacher, Mr M, walks down the coach checking all is well. “Who’s driving the bus?” asks one little girl worriedly.

Less than five minutes from school and a parent brazenly hands her son a chocolate bar. We nearby law abiders marvel at the audacity of breaking two rules with one action (see above). Mr M is still prowling the aisles and  notices the child’s tell-tale chocolate dribble. The half eaten bar is removed from his mouth. Mum is given stern look and finger wag. Everyone shifts uneasily in their seats. Obviously I won’t be giving the boys chocolate, but surely I can feed myself obesity-inducing rubbish? I resolve to eat my Penguin bar in the toilets later.

With some relief we arrive at the London Wetlands Centre without further confiscations. We deposit lunch boxes in a container and have our first toilet stop. We discover there are two toilets. Half an hour later we are still standing in a queue outside the toilets. We’ve missed the first otter feeding slot and are 10 minutes late for our stint in the playground. A mother who was at the front of the queue is starting to mutter audibly about the slowness of those at the back. Inevitably,  the last child in the queue has had an accident. We nod sympathetically and let off an inner howl as valuable playground time ticks away.

Finally we make it. Highlight of the playground is a telly tubbies-style tunnel with one entrance and, it transpires, six exits. Remaining 10 minutes of playground time is spent rounding up all those missing in the tunnel.

Next is lunch. We find our spot by following a trail of Ribena to a small patch of muddy floor overlooking a boggy lake. It’s the closest we’ve got to wildlife so far.

Later we are met by a wetlands guide who takes us to his yurt to tell us about ducks. He has pictures of food and asks the children to tell him whether it is eaten by ducks or humans. “Who eats this?” he asks, holding up a picture of a pizza. “Harry!” shout back Alec and Kit.

He tries again by asking what animals live at the Wetlands Centre.

Hands shoot up. A confident little boy is chosen.

“Giraffes”, he answers.

We then troop round to the duck pond and each child grabs a handful of pellets to lob at the ducks.

On our way out we pass the otter enclosure. They only come out at feeding time, we are told. It is not feeding time.

Our itinerary says we now have 45 minutes of “free time” which is spent wandering somewhat aimlessly with parents staring zombie-like at the café and children eyeing the giftshop. We loiter in the middle where you can neither eat nor spend money. At 1.50pm we reconvene and are the first group back on the coach. At 2.10pm everyone else arrives.

“We’ve been watching the otters being fed!” a little girl announces as she clambers on board. The front-of-the-toilet-queue mum utters a series of banned words.

The return journey is spent in virtual silence, with children and carers alike either asleep or semi-comatose with exhaustion.

Safely back at nursery, we stagger off the coach.

“What did you do?” asks Harry nonchalantly.

Alec and Kit jump around, desperate to be the first to tell him.

“We fed the ducks!” they shout in unison.