Acids on carbonates

[curie]

OK so they are doing the acids on carbonates prac where they use sea shells, marble, egg shell and snail shells. Well we seem to either be in a snail drought, or my snails are turbo charged. I planted out a bunch of lettuces, laid a half a box of snail bait, next morning all my lettuces gone, not a shell or snail trail to be found. Come to think of it I haven't seen snails in ages.
One teacher was OK and just used the other sources, one insisted she couldn't do the prac unless we had snail shells.
Anyone else had this problem? how did you get around it?

Thanks.

[J]

So the big question is: who ate your lettuces?

[curie]

No idea!

[DawnR]

I reckon we are in a snail drought here. I catch them to feed the blue tongues and shingle back lizards at school (they LOOOVE them!) but I have cleaned up all the snails at school and home, so now they are just getting lizard food from the pet shop. I wish it would rain again!!

[mtg]

Well, how interesting. I have hardly any snails and have to forage in the long grass against the fence poles for my blue tongues at home. My mother lives only 1k away and has a plague of snails. I thought it was my lizards and birds eliminating the snails, as I have no cats to scare them off.
For this prac I have sea shells, chicken, fish, and beef bones, and I gathered some old empty snail shells from the schools gardens. We do this prac for evolution using calcium carbonate as well.

[Samantham]

How do you remove the egg shell membrane so you just have the egg shell?

[bigmack]

Not sure if you mean to end up with an empty egg shell Samantham , but I recall as kids making a small hole at each end of the egg and blowing the contents of the egg out the other end . Can't remember if the membrane came out with it or not . From memory we labouriously scratch the hole with a pen knife but I guess a drill bit would be faster .And I think the exit hole was bigger .
Anyway , hope I'm not telling you how to suck eggs

[sunray18]

Have you lots of birds? I lost a whole batch of seedling lettuce to rosellas and cockatoos - they pull them right out of the ground .. and I lost all my kangaroo paws to white cockatoos - I watched them pull them out of the ground, turn them over and feast on the roots..
I have just set up a hydroponics set up in the back yard - and came out this morning to see some rosellas having a serious inspection of my seedlings..

[curie]

I've since found out possums LOOOOVE lettuce! Still no snails.
Yes, I also get quite a few birds. Maybe I should invest in some netting.