I have my data as this the ticks feed on three of the groups of treated mouse’s and compare whether my treatment has the effect on ticks the bacteria load.
When I tried to make the mixed model like below:
lmer.model01 = lmer(log10.load ~ treat + (1|mouse.id/tick.id))
My screen shows me the error as below :
Error: number of levels of each grouping factor must be < number of observations
What must have happened and how can fix this error?