The only downside is they should be kept in pairs or trios and require a pretty large habitat.
1	The	the	DET	DT	Definite=Def|PronType=Art	3	det	3:det	_
2	only	only	ADJ	JJ	Degree=Pos	3	amod	3:amod	_
3	downside	downside	NOUN	NN	Number=Sing	8	nsubj:outer	8:nsubj:outer|14:nsubj:outer	_
4	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	8	cop	8:cop	_
5	they	they	PRON	PRP	Case=Nom|Number=Plur|Person=3|PronType=Prs	8	nsubj:pass	8:nsubj:pass|14:nsubj:pass	_
6	should	should	AUX	MD	VerbForm=Fin	8	aux	8:aux	_
7	be	be	AUX	VB	VerbForm=Inf	8	aux:pass	8:aux:pass	_
8	kept	keep	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	0	root	0:root	_
9	in	in	ADP	IN	_	10	case	10:case	_
10	pairs	pair	NOUN	NNS	Number=Plur	8	obl	8:obl:in	_
11	or	or	CCONJ	CC	_	12	cc	12:cc	_
12	trios	trio	NOUN	NNS	Number=Plur	10	conj	8:obl:in|10:conj:or	_
13	and	and	CCONJ	CC	_	14	cc	14:cc	_
14	require	require	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	8	conj	0:root|8:conj:and	_
15	a	a	DET	DT	Definite=Ind|PronType=Art	18	det	18:det	_
16	pretty	pretty	ADV	RB	_	17	advmod	17:advmod	_
17	large	large	ADJ	JJ	Degree=Pos	18	amod	18:amod	_
18	habitat	habitat	NOUN	NN	Number=Sing	14	obj	14:obj	SpaceAfter=No
19	.	.	PUNCT	.	_	8	punct	8:punct	_
