Science experiment ideas

I'm assuming you've got a very limited amount of time to complete the experiment, so that limits some of my ideas. But something fairly simple like comparing the efficacy of two kinds of treatments is very doable over a short-ish period.

Protocol could look something like this:
- Measure pre-treatment mite load (%) in HIVE 1.
- Measure pre-treatment mite load (%) in HIVE 2.
- HIVE 1 gets 42 day treatment with Apivar.
- HIVE 2 gets four weekly treatments with OAV (to cover more than one drone brood cycle).
- Measure post-treatment mite load (%) in HIVE 1 after 42 days.
- Measure post-treatment mite load (%) in HIVE 2 after 42 days.
- Determine percentage of mite load decrease for each treatment method, and thereby conclude which was the most effective treatment in this case.
- Discuss upsides and downsides to each type of treatment, the need to vary treatments, the challenges for effectively treating for mites, etc.
- Discuss the limitations of this experiment (namely the very small sample, differences in colony genetics, etc.).
- Your daughter could then hypothesize why each treatment worked the way it did, and suggest a follow-on study to gain more insight.

That's just one possible route and I think fairly age-appropriate for 7th graders. Interested to hear other folks' ideas.

Couple of thoughts ...

Firstly, suggest you try to identify at least 3 possible experiments, so that your daughter is given an opportunity to choose which one she likes the sound of best - thus making it 'her' experiment.

Secondly, my own suggestion would be to construct a bee-oriented experiment rather than a hive-oriented experiment - 'cause you've only got 2 hives to work with, but many hundreds of foragers ...

So - how about placing a number of feeders, each containing a different solution, a short distance from the hives - then observe the number of bees drinking from each feeder at regular intervals throughout the day ?
The 'feeders' could be nothing more than ordinary saucers with a folded kitchen towel holding the liquid (to hopefully prevent drowning). The solutions could be (say): rainwater; tapwater; dilute sugar solution; dilute salt solution; dilute bleach solution; dilute nettle 'soup' - and so on. (Best to make up the solutions in bottles, so as to have plenty available for 'topping-up') Results could be displayed in either tabular, graphical or bar-chart format.

As far as I know, this would be a piece of original research, for I've never yet read of such an experiment being conducted. If I'm wrong on this, then no doubt someone here will correct me. I anticipate that the idea of doing something original would itself be inspiring.
'best
LJ