This is an item from Anton Moker's Decalogus metricus et paraenetica disticha, published in 1573. You can see the book at GoogleBooks.
Stercus Olet
Stercus olet tanto plus, quanto vertitur illud;
Quae mala clausa latent, haec aperire nocet.
The vocabulary is keyed to the DCC Latin Vocabulary list. There are two words in this poem that are not on the DCC list:
oleō, olēre: smell, smell like, stink
stercus (stercoris, n.): dung, manure
aperiō aperīre aperuī apertum: open
claudō claudere clausī clausum: close, shut
hic haec hoc: this; hōc: on this account
ille illa illud: that
lateō latēre latuī: lie hidden, be hidden
malus -a -um: bad, evil; male: (adv.) badly
noceō nocēre nocuī: harm
plūs plūris n.: a greater amount or number, more
quantus -a -um: (interr.) how great? (rel.) of what size, amount, etc.
qui quae quod: who, which, what / quis quid: who? what? which?
tantus -a -um: so great, so much; tantum: only
vertō vertere vertī versum: turn