When you grow your own vegetables, - especially when you're talking about lettuces and curcubits. Slugs can be your worst enemies at this time of year.
There are many different types of slugs, - it doesn't necessarily follow that the bigger they are the more they eat. But for me, if they are in my vegetable patch, then i'm at war with them. - On the footpath to the station, i'll carefully step around them, If they attack my flowers, i'll probably forgive them, but if they are after my lettuces, then they are combatants in my war, and they deserve to be taken down.
Now being an organic gardener, i'm not going to use chemicals, so over the years i've tried everything. Grit, coffee grinds, sea Shells, bran, copper collars and bands, egg shells, plus lots of others. If I find a few a couple hiding under pots when i'm at home, i'll feed them to the chickens, but when we collected a pot from the allotment last week, my girls looked at us in horror and let most of them crawl away without eating them (they prefer lettuces too!)
Unfortunately I have to let you know that although Bran is very useful and cheap in a dry year, when we've had a soaking summer it is useless.
Although Grit is good to a certain degree, if a single leaf touches the ground outside the circle of aggregate, then your plant is high level slug food.
Even putting plants in pots on shelving isn't foolproof, as I found a slug eating a sweetcorn leaf a metre off the ground last week.
So i'm using a mixture of vigilance, growing on plants until they can provide some of their own defences (courgettes get prickly leaves when they get to a certain size) keeping hiding places like long grass cut back, and a pot of death, with salt water in it, that I pop all the transgressers in to.
i've found children love slug hunting, and my school gardening club group certainly love a good hunt each week. - However with half term and an activities week meaning that we missed a couple of sessions, the slugs have overwhelmed us. - On Saturday we collected over a hundred, and these won't bother us again, but they've probably left babies to trouble us this week, so my lettuces still aren't safe.